Stockholders Equity	12 Months Ended
Dec. 31, 2011
STOCKHOLDERS' EQUITY (DEFICIT) [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	9. STOCKHOLDERS' EQUITY (DEFICIT) Initial Public Offering In November 2011, the Company issued 40,250,000 shares of Class A common stock and received approximately $744.2 million, net of underwriter fees and other issuance costs, in proceeds from the closing of an initial public offering of its Class A common stock. Convertible Preferred Stock The Company authorized 199,998 shares of Series B Convertible Preferred Stock (“Series B Preferred”), 6,560,174 shares of Series D Convertible Preferred Stock (“Series D Preferred”), 4,406,160 shares of Series E Convertible Preferred Stock (“Series E Preferred”), 4,202,658 shares of Series F Convertible Preferred Stock (“Series F Preferred”) and up to 30,075,690 shares of Series G Preferred. The Series B Preferred, Series D Preferred, Series E Preferred, Series F Preferred and Series G Preferred, collectively, are referenced below as the “Series Preferred.” The rights, preferences, privileges, restrictions and other matters relating to the Series Preferred are as follows: Series B Preferred In 2007, the Company authorized the sale and issuance of 199,998 shares of Series B Preferred for less than $0.1 million, and used the proceeds from the sale for working capital and general corporate purposes. There were 199,998 shares outstanding at December 31, 2010. The holders of Series B Preferred were entitled to annual dividends payable at a rate of 6% of the Series B Preferred original issue price. The dividends were cumulative and accrued from the date of issue while the shares were redeemable at the option of the holders. These dividend rights were subsequently rescinded by the Board in December 2010. As of December 31, 2010, there was less than $0.1 million of accrued preferred dividends due to Series B Preferred holders. The Company recorded the accrued dividends as a reduction to “Additional paid-in capital” or “Accumulated deficit.” The holders of Series B Preferred also were entitled to receive, on an as-converted to voting common stock basis, any other dividend or distribution when, as and if declared by the Board, participating equally with the holders of common stock and the holders of Series Preferred. Holders of Series B Preferred were entitled to the number of votes equal to the product obtained by multiplying (i) the number of shares of voting common stock into which their shares of Series B Preferred could be converted and (ii) 150. In addition, the Series B Preferred holders were entitled to receive, upon a liquidation event, the amount that would have been received if all shares of Series Preferred had been converted into voting common stock immediately prior to such liquidation event, only after the payment of the full Series G Preferred liquidation preference had been satisfied. If, upon the liquidating event, the assets of the Company were insufficient to fully pay the amounts owed to Series B Preferred holders, all distributions would be made ratably in proportion to the full amounts to which preferred and common stockholders would have otherwise been entitled. In the event that the Company is a party to an acquisition or asset transfer, each holder of Series B Preferred was entitled to receive the amount of cash, securities, or other property to which such holder would be entitled to receive in a liquidation event. Each share of Series B Preferred would automatically have been converted into shares of voting common stock upon the earliest of the following events to occur: (i) holders of at least 50% of the outstanding shares of Series B Preferred consent to a conversion, or (ii) upon any sale, assignment, transfer, conveyence, hypothecation or other disposition of any legal or beneficial interest in such shares, whether or not for value and whether voluntary or involuntary or by operation of law, subject to certain exceptions. The number of shares of voting common stock to which a Series B Preferred stockholder was entitled upon conversion is calculated by multiplying the applicable conversion rate then in effect (currently 12.0) by the number of Series B Preferred shares to be converted. The conversion rate for the Series B Preferred shares was subject to change in accordance with anti-dilution provisions contained in the agreement with those holders. More specifically, the conversion price was subject to adjustment to prevent dilution on a weighted‑average basis in the event that the Company issues additional shares of common stock or securities convertible or exercisable for common stock at a purchase price less than the then effective conversion price. As of December 31, 2010, 2,399,976 shares of voting common stock would have been required to be issued assuming conversion of all of the issued and outstanding shares of Series B Preferred. Series D Preferred In January 2008, the Company authorized the sale and issuance of 6,560,174 shares of Series D Preferred for $4.8 million in gross proceeds (or $4.7 million, net of issuance costs), and used the proceeds from the sale for working capital and general corporate purposes. There were 6,258,297 shares outstanding at December 31, 2010. The holders of Series D Preferred were entitled to annual dividends payable at a rate of 6% of the Series D Preferred original issue price. The dividends were cumulative and accrued from the date of issue while the shares were redeemable at the option of the holder. These dividend rights were subsequently rescinded by the Board in December 2010. As of December 31, 2010, the accrued preferred dividends due to Series D Preferred holders were $0.8 million, respectively. The Company recorded the accrued dividends as a reduction to “Additional paid-in capital” or “Accumulated deficit.” The holders of Series D Preferred also are entitled to receive, on an as-converted to voting common stock basis, any other dividend or distribution when, as and if declared by the Board, participating equally with the holders of common stock and the holders of Series Preferred. Holders of Series D Preferred were entitled to the number of votes equal to the number of shares of voting common stock into which their shares of Series D Preferred could be converted. In addition, the Series D Preferred holders were entitled to receive, upon a liquidation event, the amount that would have been received if all shares of Series Preferred had been converted into voting common stock immediately prior to such liquidation event, only after the payment of the full Series G Preferred liquidation preference has been satisfied. If, upon the liquidating event, the assets of the Company were insufficient to fully pay the amounts owed to Series D Preferred holders, all distributions would be made ratably in proportion to the full amounts to which preferred and common stockholders would have otherwise been entitled. In the event that the Company was a party to an acquisition or asset transfer, each holder of Series D Preferred was entitled to receive the amount of cash, securities, or other property to which such holder would be entitled to receive in a liquidation event. Each share of Series D Preferred would automatically have been converted into shares of voting common stock upon the earliest of the following events to occur: (i) holders of at least 50% of the outstanding shares of Series D Preferred consent to a conversion, or (ii) immediately upon the closing of an initial public offering. The number of shares of voting common stock to which a Series D Preferred stockholder was entitled upon conversion is calculated by multiplying the applicable conversion rate then in effect (currently 12.0) by the number of Series D Preferred shares to be converted. The conversion rate for the Series D Preferred shares was subject to change in accordance with anti-dilution provisions contained in the agreement with those holders. More specifically, the conversion price was subject to adjustment to prevent dilution on a weighted‑average basis in the event that the Company issues additional shares of common stock or securities convertible or exercisable for common stock at a purchase price less than the then effective conversion price. As of December 31, 2010, the number of shares of voting common stock that would have been required to be issued assuming conversion of all of the issued and outstanding shares of Series D Preferred was 75,099,564. Series E Preferred In November 2009, the Company authorized the sale and issuance of 4,406,160 shares of Series E Preferred for $30.0 million in gross proceeds (or $29.9 million, net of issuance costs), and used $26.4 million of the proceeds from the sale to fund a dividend paid to holders of the Company's capital stock on a pro-rata basis and the remainder for working capital and general corporate purposes. The Company recorded the dividend payments as a reduction to “Accumulated deficit,” and to a lesser extent, “Additional paid-in capital.” There were 4,127,653 shares outstanding at December 31, 2010. The holders of Series E Preferred were entitled to annual dividends payable at a rate of 6% of the Series E Preferred original issue price. The dividends were cumulative and accrued from the date of issue. These dividend rights were subsequently rescinded by the Board in December 2010. As of December 31, 2010, the accrued preferred dividends due to Series E Preferred holders were $0. The holders of Series E Preferred also were entitled to receive, on an as-converted to voting common stock basis, any other dividend or distribution when, as and if declared by the Board, participating equally with the holders of common stock and the holders of Series Preferred. Holders of Series E Preferred were entitled to the number of votes equal to the number of shares of voting common stock into which their shares of Series E Preferred could be converted. In addition, the Series E Preferred holders were entitled to receive, upon a liquidation event, the amount that would have been received if all shares of Series Preferred had been converted into voting common stock immediately prior to such liquidation event, only after the payment of the full Series G Preferred liquidation preference has been satisfied. If, upon the liquidating event, the assets of the Company were insufficient to fully pay the amounts owed to Series E Preferred holders, all distributions would be made ratably in proportion to the full amounts to which preferred and common stockholders would have otherwise been entitled. In the event that the Company was a party to an acquisition or asset transfer, each holder of Series E Preferred was entitled to receive the amount of cash, securities, or other property to which such holder would be entitled to receive in a liquidation event. Each share of Series E Preferred would automatically have been converted into shares of voting common stock upon the earliest of the following events to occur: (i) holders of at least 50% of the outstanding shares of Series E Preferred consent to a conversion, or (ii) immediately upon the closing of an initial public offering. The number of shares of voting common stock to which a Series E Preferred stockholder was entitled upon conversion is calculated by multiplying the applicable conversion rate then in effect (currently 12.0) by the number of Series E Preferred shares to be converted. The conversion rate for the Series E Preferred shares was subject to change in accordance with anti-dilution provisions contained in the agreement with those holders. More specifically, the conversion price was subject to adjustment to prevent dilution on a weighted‑average basis in the event that the Company issues additional shares of common stock or securities convertible or exercisable for common stock at a purchase price less than the then effective conversion price. As of December 31, 2010, the number of shares of voting common stock that would have been required to be issued assuming conversion of all of the issued and outstanding shares of Series E Preferred was 49,531,836. Series F Preferred In April 2010, the Company authorized the sale and issuance of 4,202,658 shares of Series F Preferred for $135.0 million in gross proceeds (or $134.9 million, net of issuance costs), and used $119.9 million of the proceeds from the sale to redeem shares of its outstanding common stock held by certain shareholders and the remainder for working capital and general corporate purposes. All shares of Series F Preferred were outstanding at December 31, 2010. The holders of Series F Preferred were not entitled to annual preferred dividends, but were entitled to receive, on an as-converted to voting common stock basis, any other dividend or distribution when, as and if declared by the Board, participating equally with the holders of common stock and the holders of Series Preferred. Holders of Series F Preferred were entitled to the number of votes equal to the number of shares of voting common stock into which their shares of Series F Preferred could be converted. In addition, the Series F Preferred holders were entitled to receive, upon a liquidation event, the amount that would have been received if all shares of Series Preferred had been converted into voting common stock immediately prior to such liquidation event, only after the payment of the full Series G Preferred liquidation preference has been satisfied. If, upon the liquidating event, the assets of the Company were insufficient to fully pay the amounts owed to Series F Preferred holders, all distributions would be made ratably in proportion to the full amounts to which preferred and common stockholders would have otherwise been entitled. In the event that the Company was a party to an acquisition or asset transfer, each holder of Series F Preferred was entitled to receive the amount of cash, securities, or other property to which such holder would be entitled to receive in a liquidation event. Each share of Series F Preferred would automatically have been converted into shares of voting common stock upon the earliest of the following events to occur: (i) holders of at least 50% of the outstanding shares of Series F Preferred consent to a conversion, or (ii) immediately upon the closing of an initial public offering. The number of shares of voting common stock to which a Series F Preferred stockholder was entitled upon conversion is calculated by multiplying the applicable conversion rate then in effect (currently 12.0) by the number of Series F Preferred shares to be converted. The conversion rate for the Series F Preferred shares was subject to change in accordance with anti-dilution provisions contained in the agreement with those holders. More specifically, the conversion price was subject to adjustment to prevent dilution on a weighted‑average basis in the event that the Company issues additional shares of common stock or securities convertible or exercisable for common stock at a purchase price less than the then effective conversion price. As of December 31, 2010, 50,431,896 shares of voting common stock would have been required to be issued assuming conversion of all of the issued and outstanding shares of Series F Preferred. Series G Preferred In December 2010, the Company authorized the sale of 30,075,690 shares of Series G Preferred and the initial issuance of 14,245,018 shares of Series G Preferred for $450.0 million in gross proceeds (or $449.7 million, net of issuance costs), and used $438.3 million of the proceeds from the sale to redeem shares of its outstanding common stock and preferred stock held by certain shareholders and the remainder for working capital and general corporate purposes. All issued shares of Series G Preferred were outstanding at December 31, 2010. The holders of Series G Preferred were not entitled to annual preferred dividends, but were entitled to receive, on an as-converted to voting common stock basis, any other dividend or distribution when, as and if declared by the Board, participating equally with the holders of common stock and the holders of Series Preferred. In January 2011, the Company authorized the sale and additional issuance of 15,827,796 shares of Series G Preferred for $496.0 million in gross proceeds (or $492.5 million, net of issuance costs), and used $371.5 million of the proceeds from the sale to redeem shares of its outstanding common stock and preferred stock held by certain shareholders and the remainder for working capital and general corporate purposes. Included in the additional stock issuance was 126,622 shares of Series G Preferred (or the equivalent of $4.0 million) the Company transferred to its underwriter in exchange for financial advisory services provided. Holders of Series G Preferred were entitled to the number of votes equal to the number of shares of voting common stock into which their shares of Series G Preferred could be converted. In addition, the Series G Preferred holders were entitled, before any distribution or payment is made upon any Series B Preferred, Series D Preferred, Series E Preferred, Series F Preferred or common stock, to be paid an amount per share equal to 100% of the Series G Preferred original price, plus all declared but unpaid dividends on the Series G Preferred. If, upon the liquidating event, the assets of the Company were insufficient to fully pay the amounts owed to Series G Preferred holders, all distributions would be made ratably in proportion to the full amounts to which Series G Preferred holders would have otherwise been entitled. In the event that the Company was a party to an acquisition or asset transfer, each holder of Series G Preferred was entitled to receive the amount of cash, securities, or other property to which such holder would be entitled to receive in a liquidation event. Each share of Series G Preferred would automatically have been converted into shares of voting common stock upon the earliest of the following events to occur: (i) holders of at least 50% of the outstanding shares of Series G Preferred consent to a conversion, or (ii) immediately upon the closing of an initial public offering. The number of shares of voting common stock to which a Series G Preferred stockholder wass entitled upon conversion is calculated by multiplying the applicable conversion rate then in effect (currently 4.0) by the number of Series G Preferred shares to be converted. The conversion rate for the Series G Preferred shares was subject to change in accordance with anti-dilution provisions contained in the agreement with those holders. More specifically, the conversion price was subject to adjustment to prevent dilution on a weighted‑average basis in the event that the Company issues additional shares of common stock or securities convertible or exercisable for common stock at a purchase price less than the then effective conversion price. As of December 31, 2010, 56,980,072 shares of voting common stock would have been required to be issued assuming conversion of all of the issued and outstanding shares of Series G Preferred. Series Preferred On October 31, 2011, each outstanding share of Series D preferred stock, Series E preferred stock and Series F preferred stock was converted into twelve shares of Class A common stock and each outstanding share of our Series G preferred stock was converted into four shares of Class A common stock. This resulted in the issuance of 290,909,740 shares of Class A common stock. In addition, each outstanding share of Series B preferred stock was converted into twelve shares of Class B common stock. This resulted in the issuance of 2,399,976 shares of Class B common stock. The Board has the authority, without approval by the stockholders, to issue up to a total of 50,000,000 shares of preferred stock in one or more series. The Board may establish the number of shares to be included in each such series and may fix the designations, preferences, powers and other rights of the shares of a series of preferred stock. The Board could authorize the issuance of preferred stock with voting or conversion rights that could dilute the voting power or rights of the holders of the Class A common stock or Class B common stock. As of December 31, 2011, there were no shares of Series Preferred stock outstanding. Common Stock The Board has authorized three classes of common stock: Class A common stock, Class B common stock and common stock. No shares of common stock will be issued or outstanding until November 5, 2016 at which time all outstanding shares of Class A common stock and Class B common stock will automatically convert into shares of common stock. In addition, the Board authorized shares of undesignated preferred stock, the rights, preferences and privileges of which may be designated from time to time by the Board. The total amount of our authorized common stock will consist of 4,020,000,000 shares, all with a par value of $0.0001 per share, of which 2,000,000,000 shares are designated as Class A common stock, 10,000,000 shares are designated as Class B common stock, 2,010,000,000 shares are designated as common stock. On December 31, 2011, we had outstanding 641,745,225 shares of Class A common stock and 2,399,976 shares of Class B common stock. Holders of our Class A common stock and Class B common stock have identical rights, except that holders of our Class A common stock are entitled to one vote per share and holders of our Class B common stock are entitled to 150 votes per share. Holders of shares of Class A common stock and Class B common stock will vote together as a single class on all matters (including the election of directors) submitted to a vote of stockholders, except that there will be separate votes of holders of shares of the Class A common stock and Class B common stock in the following circumstances: • if the Company proposes to amend our amended and restated certificate of incorporation to alter or change the powers, preferences or special rights of the shares of a class of its stock so as to affect them adversely or to increase or decrease the par value of the shares of a class of the Company's stock; • if the Company proposes to treat the shares of a class of its stock differently with respect to any dividend or distribution of cash, property or shares of our stock paid or distributed by the Company; • if the Company proposes to treat the shares of a class of its stock differently with respect to any subdivision or combination of the shares of a class of the Company's stock; or • if the Company proposes to treat the shares of a class of its stock differently in connection with a change in control, liquidation, dissolution, distribution of assets or winding down of the Company with respect to any consideration into which the shares are converted or any consideration paid or otherwise distributed to its stockholders. The Company may not increase or decrease the authorized number of shares of Class A common stock or Class B common stock without the affirmative vote of the holders of the majority of the combined voting power of the outstanding shares of Class A common stock and Class B common stock, voting together as a single class. In addition, the Company may not issue any shares of Class B common stock, other than in connection with stock dividends, stock splits and similar transactions, unless that issuance is approved by the affirmative vote of the holders of a majority of the outstanding shares of Class B common stock. There is no cumulative voting for the election of directors. Except as otherwise expressly provided in the Company's amended and restated certificate of incorporation or as required by applicable law, shares of our Class A common stock and Class B common stock will have the same rights and privileges and rank equally, share ratably and be identical in all respects as to all matters, including, without limitation, those described below. Subject to preferences that may apply to any shares of preferred stock outstanding at the time, the holders of Class A common stock and Class B common stock shall be entitled to share equally, ratably and identically, on a per share basis, with respect to any dividends that the Board may determine to issue from time to time, unless different treatment of the shares of such class is approved by the affirmative vote of the holders of the majority of the outstanding shares of Class A common stock and Class B common stock, each voting separately as a class. In the event a dividend is paid in the form of shares of common stock or rights to acquire shares of common stock, the holders of Class A common stock shall receive shares of Class A common stock, or rights to acquire shares of Class A common stock, as the case may be, and the holders of Class B common stock shall receive shares of Class B common stock, or rights to acquire shares of Class B common stock, as the case may be. Upon our liquidation, dissolution or winding-up, the holders of Class A common stock and Class B common stock shall be entitled to share equally, ratably and identically in all assets remaining after the payment of any liabilities and the liquidation preferences on any outstanding preferred stock, unless different treatment of the shares of such class is approved by the affirmative vote of the holders of the majority of the outstanding shares of Class A common stock and Class B common stock, each voting separately as a class. Upon (i) the closing of the sale, transfer or other disposition of all or substantially all of our assets, (ii) the consummation of a merger, consolidation, business combination or other similar transaction which results in our voting securities outstanding immediately prior to the transaction (or the voting securities issued with respect to our voting securities outstanding immediately prior to the transaction) representing less than a majority of the combined voting power and outstanding capital stock of the voting securities of the Company or the surviving or acquiring entity, (iii) the recapitalization, liquidation, dissolution or other similar transaction which results in the voting securities outstanding immediately prior to the transaction representing less than a majority of the combined voting power and outstanding capital stock of the Company or the surviving entity or parent entity or (iv) an issuance by the Company, in one transaction or a series of related transactions, of voting securities representing more than 2% of the total voting power of the Company (assuming the Class A common stock and Class B common stock each have one vote per share) to any person or group of affiliated persons who prior to such issuance held less than a majority of the total voting power of the Company (assuming the Class A common stock and Class B common stock each have one vote per share) and who subsequent to the issuance would hold a majority of the total voting power, the holders of Class A common stock and Class B common stock will be treated equally and identically with respect to shares of Class A common stock or Class B common stock owned by them, unless different treatment of the shares of each class is approved by the affirmative vote of the holders of a majority of the outstanding shares of Class A common stock and Class B common stock, each voting separately as a class. If the Company subdivides or combines in any manner outstanding shares of Class A common stock or Class B common stock, the outstanding shares of the other class will be subdivided or combined in the same manner, unless different treatment of the shares of each class is approved by the affirmative vote of the holders of a majority of the outstanding shares of Class A common stock and Class B common stock, each voting separately as a class. The Company issues stock-based awards to its employees in the form of stock options, restricted stock units and restricted stock. See Note 10 "Stock-Based Compensation". Stock Repurchase Activity In April 2010 and December 2010, the Board authorized the Company to repurchase shares of its capital stock held by certain holders, using a portion of the proceeds from the sale of Series F Preferred and the sale of Series G Preferred, respectively. The Company repurchased 93,328,656 shares of common stock for $503.2 million, and 580,384 shares of preferred stock for $55.0 million in 2010. Total shares repurchased from Company employees were 4,370,959. In 2011, the Company repurchased 45,090,184 shares of common stock for $353.8 million and 370,401 shares of preferred stock for $35.0 million. Return of Common Shares On September 22, 2011, the Company's chief operating officer resigned. As a result of the separation agreement, 400,000 shares of non-voting common stock were returned resulting in other income of approximately $4.9 million, which represents the reversal of the originally recognized stock compensation expense and is included in interest and other income (expense), net within the consolidated statements of operations for the year ended December 31, 2011. Treasury Stock As of December 31, 2010, there were 93,328,656 shares of treasury stock. On October 31, 2011, all shares of treasury stock were cancelled in conjunction with the recapitalization prior to the initial public offering. As of December 31, 2011, there were no shares of treasury stock.

9. STOCKHOLDERS' EQUITY (DEFICIT)

Initial Public Offering

In November 2011, the Company issued 40,250,000 shares of Class A common stock and received approximately $744.2 million, net of underwriter fees and other issuance costs, in proceeds from the closing of an initial public offering of its Class A common stock.

Convertible Preferred Stock

The Company authorized 199,998 shares of Series B Convertible Preferred Stock (“Series B Preferred”), 6,560,174 shares of Series D Convertible Preferred Stock (“Series D Preferred”), 4,406,160 shares of Series E Convertible Preferred Stock (“Series E Preferred”), 4,202,658 shares of Series F Convertible Preferred Stock (“Series F Preferred”) and up to 30,075,690 shares of Series G Preferred. The Series B Preferred, Series D Preferred, Series E Preferred, Series F Preferred and Series G Preferred, collectively, are referenced below as the “Series Preferred.” The rights, preferences, privileges, restrictions and other matters relating to the Series Preferred are as follows:

Series B Preferred

In 2007, the Company authorized the sale and issuance of 199,998 shares of Series B Preferred for less than $0.1 million, and used the proceeds from the sale for working capital and general corporate purposes. There were 199,998 shares outstanding at December 31, 2010. The holders of Series B Preferred were entitled to annual dividends payable at a rate of 6% of the Series B Preferred original issue price. The dividends were cumulative and accrued from the date of issue while the shares were redeemable at the option of the holders. These dividend rights were subsequently rescinded by the Board in December 2010. As of December 31, 2010, there was less than $0.1 million of accrued preferred dividends due to Series B Preferred holders. The Company recorded the accrued dividends as a reduction to “Additional paid-in capital” or “Accumulated deficit.” The holders of Series B Preferred also were entitled to receive, on an as-converted to voting common stock basis, any other dividend or distribution when, as and if declared by the Board, participating equally with the holders of common stock and the holders of Series Preferred.

Holders of Series B Preferred were entitled to the number of votes equal to the product obtained by multiplying (i) the number of shares of voting common stock into which their shares of Series B Preferred could be converted and (ii) 150. In addition, the Series B Preferred holders were entitled to receive, upon a liquidation event, the amount that would have been received if all shares of Series Preferred had been converted into voting common stock immediately prior to such liquidation event, only after the payment of the full Series G Preferred liquidation preference had been satisfied. If, upon the liquidating event, the assets of the Company were insufficient to fully pay the amounts owed to Series B Preferred holders, all distributions would be made ratably in proportion to the full amounts to which preferred and common stockholders would have otherwise been entitled. In the event that the Company is a party to an acquisition or asset transfer, each holder of Series B Preferred was entitled to receive the amount of cash, securities, or other property to which such holder would be entitled to receive in a liquidation event.

Each share of Series B Preferred would automatically have been converted into shares of voting common stock upon the earliest of the following events to occur: (i) holders of at least 50% of the outstanding shares of Series B Preferred consent to a conversion, or (ii) upon any sale, assignment, transfer, conveyence, hypothecation or other disposition of any legal or beneficial interest in such shares, whether or not for value and whether voluntary or involuntary or by operation of law, subject to certain exceptions. The number of shares of voting common stock to which a Series B Preferred stockholder was entitled upon conversion is calculated by multiplying the applicable conversion rate then in effect (currently 12.0) by the number of Series B Preferred shares to be converted. The conversion rate for the Series B Preferred shares was subject to change in accordance with anti-dilution provisions contained in the agreement with those holders. More specifically, the conversion price was subject to adjustment to prevent dilution on a weighted‑average basis in the event that the Company issues additional shares of common stock or securities convertible or exercisable for common stock at a purchase price less than the then effective conversion price. As of December 31, 2010, 2,399,976 shares of voting common stock would have been required to be issued assuming conversion of all of the issued and outstanding shares of Series B Preferred.

Series D Preferred

In January 2008, the Company authorized the sale and issuance of 6,560,174 shares of Series D Preferred for $4.8 million in gross proceeds (or $4.7 million, net of issuance costs), and used the proceeds from the sale for working capital and general corporate purposes. There were 6,258,297 shares outstanding at December 31, 2010. The holders of Series D Preferred were entitled to annual dividends payable at a rate of 6% of the Series D Preferred original issue price. The dividends were cumulative and accrued from the date of issue while the shares were redeemable at the option of the holder. These dividend rights were subsequently rescinded by the Board in December 2010. As of December 31, 2010, the accrued preferred dividends due to Series D Preferred holders were $0.8 million, respectively. The Company recorded the accrued dividends as a reduction to “Additional paid-in capital” or “Accumulated deficit.” The holders of Series D Preferred also are entitled to receive, on an as-converted to voting common stock basis, any other dividend or distribution when, as and if declared by the Board, participating equally with the holders of common stock and the holders of Series Preferred.

Holders of Series D Preferred were entitled to the number of votes equal to the number of shares of voting common stock into which their shares of Series D Preferred could be converted. In addition, the Series D Preferred holders were entitled to receive, upon a liquidation event, the amount that would have been received if all shares of Series Preferred had been converted into voting common stock immediately prior to such liquidation event, only after the payment of the full Series G Preferred liquidation preference has been satisfied. If, upon the liquidating event, the assets of the Company were insufficient to fully pay the amounts owed to Series D Preferred holders, all distributions would be made ratably in proportion to the full amounts to which preferred and common stockholders would have otherwise been entitled. In the event that the Company was a party to an acquisition or asset transfer, each holder of Series D Preferred was entitled to receive the amount of cash, securities, or other property to which such holder would be entitled to receive in a liquidation event.

Each share of Series D Preferred would automatically have been converted into shares of voting common stock upon the earliest of the following events to occur: (i) holders of at least 50% of the outstanding shares of Series D Preferred consent to a conversion, or (ii) immediately upon the closing of an initial public offering. The number of shares of voting common stock to which a Series D Preferred stockholder was entitled upon conversion is calculated by multiplying the applicable conversion rate then in effect (currently 12.0) by the number of Series D Preferred shares to be converted. The conversion rate for the Series D Preferred shares was subject to change in accordance with anti-dilution provisions contained in the agreement with those holders. More specifically, the conversion price was subject to adjustment to prevent dilution on a weighted‑average basis in the event that the Company issues additional shares of common stock or securities convertible or exercisable for common stock at a purchase price less than the then effective conversion price. As of December 31, 2010, the number of shares of voting common stock that would have been required to be issued assuming conversion of all of the issued and outstanding shares of Series D Preferred was 75,099,564.

Series E Preferred

In November 2009, the Company authorized the sale and issuance of 4,406,160 shares of Series E Preferred for $30.0 million in gross proceeds (or $29.9 million, net of issuance costs), and used $26.4 million of the proceeds from the sale to fund a dividend paid to holders of the Company's capital stock on a pro-rata basis and the remainder for working capital and general corporate purposes. The Company recorded the dividend payments as a reduction to “Accumulated deficit,” and to a lesser extent, “Additional paid-in capital.” There were 4,127,653 shares outstanding at December 31, 2010. The holders of Series E Preferred were entitled to annual dividends payable at a rate of 6% of the Series E Preferred original issue price. The dividends were cumulative and accrued from the date of issue. These dividend rights were subsequently rescinded by the Board in December 2010. As of December 31, 2010, the accrued preferred dividends due to Series E Preferred holders were $0. The holders of Series E Preferred also were entitled to receive, on an as-converted to voting common stock basis, any other dividend or distribution when, as and if declared by the Board, participating equally with the holders of common stock and the holders of Series Preferred.

Holders of Series E Preferred were entitled to the number of votes equal to the number of shares of voting common stock into which their shares of Series E Preferred could be converted. In addition, the Series E Preferred holders were entitled to receive, upon a liquidation event, the amount that would have been received if all shares of Series Preferred had been converted into voting common stock immediately prior to such liquidation event, only after the payment of the full Series G Preferred liquidation preference has been satisfied. If, upon the liquidating event, the assets of the Company were insufficient to fully pay the amounts owed to Series E Preferred holders, all distributions would be made ratably in proportion to the full amounts to which preferred and common stockholders would have otherwise been entitled. In the event that the Company was a party to an acquisition or asset transfer, each holder of Series E Preferred was entitled to receive the amount of cash, securities, or other property to which such holder would be entitled to receive in a liquidation event.

Each share of Series E Preferred would automatically have been converted into shares of voting common stock upon the earliest of the following events to occur: (i) holders of at least 50% of the outstanding shares of Series E Preferred consent to a conversion, or (ii) immediately upon the closing of an initial public offering. The number of shares of voting common stock to which a Series E Preferred stockholder was entitled upon conversion is calculated by multiplying the applicable conversion rate then in effect (currently 12.0) by the number of Series E Preferred shares to be converted. The conversion rate for the Series E Preferred shares was subject to change in accordance with anti-dilution provisions contained in the agreement with those holders. More specifically, the conversion price was subject to adjustment to prevent dilution on a weighted‑average basis in the event that the Company issues additional shares of common stock or securities convertible or exercisable for common stock at a purchase price less than the then effective conversion price. As of December 31, 2010, the number of shares of voting common stock that would have been required to be issued assuming conversion of all of the issued and outstanding shares of Series E Preferred was 49,531,836.

Series F Preferred

In April 2010, the Company authorized the sale and issuance of 4,202,658 shares of Series F Preferred for $135.0 million in gross proceeds (or $134.9 million, net of issuance costs), and used $119.9 million of the proceeds from the sale to redeem shares of its outstanding common stock held by certain shareholders and the remainder for working capital and general corporate purposes. All shares of Series F Preferred were outstanding at December 31, 2010. The holders of Series F Preferred were not entitled to annual preferred dividends, but were entitled to receive, on an as-converted to voting common stock basis, any other dividend or distribution when, as and if declared by the Board, participating equally with the holders of common stock and the holders of Series Preferred.

Holders of Series F Preferred were entitled to the number of votes equal to the number of shares of voting common stock into which their shares of Series F Preferred could be converted. In addition, the Series F Preferred holders were entitled to receive, upon a liquidation event, the amount that would have been received if all shares of Series Preferred had been converted into voting common stock immediately prior to such liquidation event, only after the payment of the full Series G Preferred liquidation preference has been satisfied. If, upon the liquidating event, the assets of the Company were insufficient to fully pay the amounts owed to Series F Preferred holders, all distributions would be made ratably in proportion to the full amounts to which preferred and common stockholders would have otherwise been entitled. In the event that the Company was a party to an acquisition or asset transfer, each holder of Series F Preferred was entitled to receive the amount of cash, securities, or other property to which such holder would be entitled to receive in a liquidation event.

Each share of Series F Preferred would automatically have been converted into shares of voting common stock upon the earliest of the following events to occur: (i) holders of at least 50% of the outstanding shares of Series F Preferred consent to a conversion, or (ii) immediately upon the closing of an initial public offering. The number of shares of voting common stock to which a Series F Preferred stockholder was entitled upon conversion is calculated by multiplying the applicable conversion rate then in effect (currently 12.0) by the number of Series F Preferred shares to be converted. The conversion rate for the Series F Preferred shares was subject to change in accordance with anti-dilution provisions contained in the agreement with those holders. More specifically, the conversion price was subject to adjustment to prevent dilution on a weighted‑average basis in the event that the Company issues additional shares of common stock or securities convertible or exercisable for common stock at a purchase price less than the then effective conversion price. As of December 31, 2010, 50,431,896 shares of voting common stock would have been required to be issued assuming conversion of all of the issued and outstanding shares of Series F Preferred.

Series G Preferred

In December 2010, the Company authorized the sale of 30,075,690 shares of Series G Preferred and the initial issuance of 14,245,018 shares of Series G Preferred for $450.0 million in gross proceeds (or $449.7 million, net of issuance costs), and used $438.3 million of the proceeds from the sale to redeem shares of its outstanding common stock and preferred stock held by certain shareholders and the remainder for working capital and general corporate purposes. All issued shares of Series G Preferred were outstanding at December 31, 2010. The holders of Series G Preferred were not entitled to annual preferred dividends, but were entitled to receive, on an as-converted to voting common stock basis, any other dividend or distribution when, as and if declared by the Board, participating equally with the holders of common stock and the holders of Series Preferred.

In January 2011, the Company authorized the sale and additional issuance of 15,827,796 shares of Series G Preferred for $496.0 million in gross proceeds (or $492.5 million, net of issuance costs), and used $371.5 million of the proceeds from the sale to redeem shares of its outstanding common stock and preferred stock held by certain shareholders and the remainder for working capital and general corporate purposes. Included in the additional stock issuance was 126,622 shares of Series G Preferred (or the equivalent of $4.0 million) the Company transferred to its underwriter in exchange for financial advisory services provided.

Holders of Series G Preferred were entitled to the number of votes equal to the number of shares of voting common stock into which their shares of Series G Preferred could be converted. In addition, the Series G Preferred holders were entitled, before any distribution or payment is made upon any Series B Preferred, Series D Preferred, Series E Preferred, Series F Preferred or common stock, to be paid an amount per share equal to 100% of the Series G Preferred original price, plus all declared but unpaid dividends on the Series G Preferred. If, upon the liquidating event, the assets of the Company were insufficient to fully pay the amounts owed to Series G Preferred holders, all distributions would be made ratably in proportion to the full amounts to which Series G Preferred holders would have otherwise been entitled. In the event that the Company was a party to an acquisition or asset transfer, each holder of Series G Preferred was entitled to receive the amount of cash, securities, or other property to which such holder would be entitled to receive in a liquidation event.

Each share of Series G Preferred would automatically have been converted into shares of voting common stock upon the earliest of the following events to occur: (i) holders of at least 50% of the outstanding shares of Series G Preferred consent to a conversion, or (ii) immediately upon the closing of an initial public offering. The number of shares of voting common stock to which a Series G Preferred stockholder wass entitled upon conversion is calculated by multiplying the applicable conversion rate then in effect (currently 4.0) by the number of Series G Preferred shares to be converted. The conversion rate for the Series G Preferred shares was subject to change in accordance with anti-dilution provisions contained in the agreement with those holders. More specifically, the conversion price was subject to adjustment to prevent dilution on a weighted‑average basis in the event that the Company issues additional shares of common stock or securities convertible or exercisable for common stock at a purchase price less than the then effective conversion price. As of December 31, 2010, 56,980,072 shares of voting common stock would have been required to be issued assuming conversion of all of the issued and outstanding shares of Series G Preferred.

Series Preferred

On October 31, 2011, each outstanding share of Series D preferred stock, Series E preferred stock and Series F preferred stock was converted into twelve shares of Class A common stock and each outstanding share of our Series G preferred stock was converted into four shares of Class A common stock. This resulted in the issuance of 290,909,740 shares of Class A common stock. In addition, each outstanding share of Series B preferred stock was converted into twelve shares of Class B common stock. This resulted in the issuance of 2,399,976 shares of Class B common stock.

The Board has the authority, without approval by the stockholders, to issue up to a total of 50,000,000 shares of preferred stock in one or more series. The Board may establish the number of shares to be included in each such series and may fix the designations, preferences, powers and other rights of the shares of a series of preferred stock. The Board could authorize the issuance of preferred stock with voting or conversion rights that could dilute the voting power or rights of the holders of the Class A common stock or Class B common stock.

As of December 31, 2011, there were no shares of Series Preferred stock outstanding.

Common Stock

The Board has authorized three classes of common stock: Class A common stock, Class B common stock and common stock. No shares of common stock will be issued or outstanding until November 5, 2016 at which time all outstanding shares of Class A common stock and Class B common stock will automatically convert into shares of common stock. In addition, the Board authorized shares of undesignated preferred stock, the rights, preferences and privileges of which may be designated from time to time by the Board.

The total amount of our authorized common stock will consist of 4,020,000,000 shares, all with a par value of $0.0001 per share, of which 2,000,000,000 shares are designated as Class A common stock, 10,000,000 shares are designated as Class B common stock, 2,010,000,000 shares are designated as common stock. On December 31, 2011, we had outstanding 641,745,225 shares of Class A common stock and 2,399,976 shares of Class B common stock.

Holders of our Class A common stock and Class B common stock have identical rights, except that holders of our Class A common stock are entitled to one vote per share and holders of our Class B common stock are entitled to 150 votes per share. Holders of shares of Class A common stock and Class B common stock will vote together as a single class on all matters (including the election of directors) submitted to a vote of stockholders, except that there will be separate votes of holders of shares of the Class A common stock and Class B common stock in the following circumstances:

• if the Company proposes to amend our amended and restated certificate of incorporation to alter or change the powers, preferences or special rights of the shares of a class of its stock so as to affect them adversely or to increase or decrease the par value of the shares of a class of the Company's stock;

• if the Company proposes to treat the shares of a class of its stock differently with respect to any dividend or distribution of cash, property or shares of our stock paid or distributed by the Company;

• if the Company proposes to treat the shares of a class of its stock differently with respect to any subdivision or combination of the shares of a class of the Company's stock; or

• if the Company proposes to treat the shares of a class of its stock differently in connection with a change in control, liquidation, dissolution, distribution of assets or winding down of the Company with respect to any consideration into which the shares are converted or any consideration paid or otherwise distributed to its stockholders.

The Company may not increase or decrease the authorized number of shares of Class A common stock or Class B common stock without the affirmative vote of the holders of the majority of the combined voting power of the outstanding shares of Class A common stock and Class B common stock, voting together as a single class. In addition, the Company may not issue any shares of Class B common stock, other than in connection with stock dividends, stock splits and similar transactions, unless that issuance is approved by the affirmative vote of the holders of a majority of the outstanding shares of Class B common stock. There is no cumulative voting for the election of directors.

Except as otherwise expressly provided in the Company's amended and restated certificate of incorporation or as required by applicable law, shares of our Class A common stock and Class B common stock will have the same rights and privileges and rank equally, share ratably and be identical in all respects as to all matters, including, without limitation, those described below.

Subject to preferences that may apply to any shares of preferred stock outstanding at the time, the holders of Class A common stock and Class B common stock shall be entitled to share equally, ratably and identically, on a per share basis, with respect to any dividends that the Board may determine to issue from time to time, unless different treatment of the shares of such class is approved by the affirmative vote of the holders of the majority of the outstanding shares of Class A common stock and Class B common stock, each voting separately as a class. In the event a dividend is paid in the form of shares of common stock or rights to acquire shares of common stock, the holders of Class A common stock shall receive shares of Class A common stock, or rights to acquire shares of Class A common stock, as the case may be, and the holders of Class B common stock shall receive shares of Class B common stock, or rights to acquire shares of Class B common stock, as the case may be.

Upon our liquidation, dissolution or winding-up, the holders of Class A common stock and Class B common stock shall be entitled to share equally, ratably and identically in all assets remaining after the payment of any liabilities and the liquidation preferences on any outstanding preferred stock, unless different treatment of the shares of such class is approved by the affirmative vote of the holders of the majority of the outstanding shares of Class A common stock and Class B common stock, each voting separately as a class.

Upon (i) the closing of the sale, transfer or other disposition of all or substantially all of our assets, (ii) the consummation of a merger, consolidation, business combination or other similar transaction which results in our voting securities outstanding immediately prior to the transaction (or the voting securities issued with respect to our voting securities outstanding immediately prior to the transaction) representing less than a majority of the combined voting power and outstanding capital stock of the voting securities of the Company or the surviving or acquiring entity, (iii) the recapitalization, liquidation, dissolution or other similar transaction which results in the voting securities outstanding immediately prior to the transaction representing less than a majority of the combined voting power and outstanding capital stock of the Company or the surviving entity or parent entity or (iv) an issuance by the Company, in one transaction or a series of related transactions, of voting securities representing more than 2% of the total voting power of the Company (assuming the Class A common stock and Class B common stock each have one vote per share) to any person or group of affiliated persons who prior to such issuance held less than a majority of the total voting power of the Company (assuming the Class A common stock and Class B common stock each have one vote per share) and who subsequent to the issuance would hold a majority of the total voting power, the holders of Class A common stock and Class B common stock will be treated equally and identically with respect to shares of Class A common stock or Class B common stock owned by them, unless different treatment of the shares of each class is approved by the affirmative vote of the holders of a majority of the outstanding shares of Class A common stock and Class B common stock, each voting separately as a class.

If the Company subdivides or combines in any manner outstanding shares of Class A common stock or Class B common stock, the outstanding shares of the other class will be subdivided or combined in the same manner, unless different treatment of the shares of each class is approved by the affirmative vote of the holders of a majority of the outstanding shares of Class A common stock and Class B common stock, each voting separately as a class.

The Company issues stock-based awards to its employees in the form of stock options, restricted stock units and restricted stock. See Note 10 "Stock-Based Compensation".

Stock Repurchase Activity

In April 2010 and December 2010, the Board authorized the Company to repurchase shares of its capital stock held by certain holders, using a portion of the proceeds from the sale of Series F Preferred and the sale of Series G Preferred, respectively. The Company repurchased 93,328,656 shares of common stock for $503.2 million, and 580,384 shares of preferred stock for $55.0 million in 2010. Total shares repurchased from Company employees were 4,370,959. In 2011, the Company repurchased 45,090,184 shares of common stock for $353.8 million and 370,401 shares of preferred stock for $35.0 million.

Return of Common Shares

On September 22, 2011, the Company's chief operating officer resigned. As a result of the separation agreement, 400,000 shares of non-voting common stock were returned resulting in other income of approximately $4.9 million, which represents the reversal of the originally recognized stock compensation expense and is included in interest and other income (expense), net within the consolidated statements of operations for the year ended December 31, 2011.

Treasury Stock

As of December 31, 2010, there were 93,328,656 shares of treasury stock. On October 31, 2011, all shares of treasury stock were cancelled in conjunction with the recapitalization prior to the initial public offering. As of December 31, 2011, there were no shares of treasury stock.