Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2013

A summary of stock option activity under the Plan as of September 30, 2013, and the changes during the nine months then ended is as follows:


	Number of Shares			Weighted Average Exercise Price ($)		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value ($)
Outstanding at December 31, 2012		7,814,561			1.49
Granted		904,380			4.01
Exercised		(707,285	)		0.72				2,379,554
Cancelled		(197,276	)		3.49

Outstanding at September 30, 2013		7,814,380			1.80		6.4		17,703,665

Exercisable at September 30, 2013		6,234,160			1.38		5.7		16,696,929

Assumptions Used in Fair Value Measurement of Options Granted


	September 30,
	2013			2012
Risk-free interest rate		0.7	%		0.7	%
Annualized volatility		62.5	%		61.0	%
Weighted average expected life, in years		6.0			5.0
Expected dividend yield		0.0	%		0.0	%

Schedule of Performance Stock Unit Awards and Stock Option Granted Under Long Term Incentive Program

The performance stock unit awards, restricted stock and stock options granted under the long term incentive program are summarized in the following table:


	Performance Stock Units				Restricted Stock				Stock Options
Grant Date	Number of Shares		Fair Value on Grant Date		Number of Shares		Fair Value on Grant Date		Number of Options		Exercise Price
May 17, 2011		182,000	$	1.66		—		—		317,000	$	1.66
May 17, 2012		—		—		—		—		470,000	$	2.94
July 6, 2012		137,715	$	4.26		—		—		178,731	$	4.26
May 22, 2013		185,185	$	3.96		185,185	$	3.96		327,381	$	3.96