
	Year ended December 31,
	2022		2021		2020
Cost of revenues	$	34,269	$	29,307	$	14,275
Research and development	88,846		83,042		39,283
Sales and marketing	151,950		137,924		64,240
General and administrative	110,944		107,692		71,802
Total share-based compensation expense	$	386,009	$	357,965	$	189,600


	Year ended December 31,
	2022		2021		2020
Options	$	—	$	1	$	44
Employee stock purchase plan rights	7,719		9,573		7,161
Restricted stock units	378,290		348,391		182,395
Total share-based compensation expense	$	386,009	$	357,965	$	189,600

In September 2013, the Board adopted and the Company’s stockholders approved the 2013 Equity Incentive Plan, which became effective on September 26, 2013, and the stockholders approved an amended and restated 2013 Equity Plan on December 15, 2022 (together, “2013 Plan”). In connection with the adoption of the 2013 Plan, the Company terminated the 2010 Equity Incentive Plan (“2010 Plan”), under which stock options had been granted prior to September 26, 2013. The 2010 Plan was established in September 2010, when the 2003 Equity Incentive Plan (“2003 Plan”) was terminated. After the termination of the 2003 and 2010 Plans, no additional options were granted under these plans; however, options previously granted under these plans will continue to be governed by these plans and will be exercisable into shares of Class B Common Stock. In addition, options authorized to be granted under the 2003 and 2010 Plans, including forfeitures of previously granted awards, are authorized for grant under the 2013 Plan.

A total of 6,200,000 shares of Class A Common Stock were originally reserved for issuance under the 2013 Plan. The 2013 Plan includes an annual increase on the first day of each fiscal year beginning in 2014, equal to the least of: (i) 6,200,000 shares of Class A Common Stock; (ii) 5% of the outstanding shares of all classes of common stock as of the last day of the Company’s immediately preceding fiscal year; or (iii) such other amount as the board of directors may determine. During the year ended December 31, 2022, a total of 4,715,470 shares of Class A Common Stock were added to the 2013 Plan in connection with the annual automatic increase provision. As of December 31, 2022, a total of 19,648,499 shares remain available for grant under the 2013 Plan.

The plans permit the grant of stock options and other share-based awards, such as restricted stock units, to employees, officers, directors, and consultants by the board of directors. Option awards are generally granted with an exercise price equal to the fair market value of the Company’s Class A Common Stock at the date of grant. Option awards generally vest according to a graded vesting schedule based on four years of continuous service. On January 29, 2014, the board of directors approved an amendment to decrease the contractual term of all equity awards issued from the 2013 Plan from 10 years to 7 years for all awards granted after January 29, 2014. Certain option awards provide for accelerated vesting if there is a change in control (as defined in the option agreement) and early exercise of options prior to vesting (subject to the Company’s repurchase right).


	Number of Options Outstanding (in thousands)	Weighted- Average Exercise Price Per Share		Weighted- Average Contractual Term (in Years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2019	2,257	$	13.13	2.5	$	351,428

Exercised	(1,360)	13.87
Canceled/Forfeited	—	—
Outstanding at December 31, 2020	897	$	12.02	1.7	$	329,151

Exercised	(741)	12.58
Canceled/Forfeited	(2)	27.45
Outstanding at December 31, 2021	154	$	9.12	0.9	$	27,465

Exercised	(132)	8.54
Canceled/Forfeited	—	—
Outstanding at December 31, 2022	22	$	12.53	0.5	$	509
Vested and expected to vest as of December 31, 2022	22	$	12.53	0.5	$	509
Exercisable as of December 31, 2022	22	$	12.53	0.5	$	509

There were no options granted for the year ended December 31, 2022 and 2021. The total intrinsic value of options exercised during year ended December 31, 2022, 2021 and 2020 were $13.6 million, $190.7 million, and $343.7 million, respectively. There is no remaining unamortized share-based compensation expense related to options.

The Company’s Employee Stock Purchase Plan (“ESPP”) allows eligible employees to purchase shares of the Company’s Class A Common Stock at a discounted price, through payroll deductions of up to the lesser of 15% of their eligible compensation or the IRS allowable limit per calendar year. A participant may purchase a maximum of 3,000 shares during an offering period. The offering periods are for a period of six months and generally start on the first trading day on or after May 13th and November 13th of each year. At the end of the offering period, the purchase price is set at the lower of: (i) 85% of the fair value of the Company’s common stock at the beginning of the six-month offering period and (ii) 85% of the fair value of the Company’s Class A Common Stock at the end of the six-month offering period.

The ESPP provides for annual increases in the number of shares available for issuance under the ESPP on the first day of each fiscal year beginning in fiscal 2014, equal to the least of: (i) 1% of the outstanding shares of all classes of common stock on the last day of the immediately preceding year; (ii) 1,250,000 shares; or (iii) such other amount as may be determined by the board of directors. During the year ended December 31, 2022, a total of 943,094 shares of Class A Common Stock were added to the ESPP Plan in connection with the annual increase provision. At December 31, 2022, a total of 6,054,525 shares were available for issuance under the ESPP.

The weighted-average assumptions used to value ESPP rights under the Black-Scholes-Merton option-pricing model and the resulting offering grant date fair value of ESPP rights granted in the periods presented were as follows:


	Year ended December 31,
	2022			2021			2020
Expected term (in years)	0.5			0.5			0.5
Expected volatility	81		%	48		%	63		%
Risk-free interest rate	3.01		%	0.05		%	0.13		%
Expected dividend yield	0		%	0		%	0		%
Offering grant date fair value of ESPP rights	$	20.18		$	71.27		$	79.85

As of December 31, 2022 and 2021, there was approximately $4.4 million and $4.2 million of unrecognized share-based compensation expense, net of estimated forfeitures, related to ESPP, which will be recognized on a straight-line basis over the remaining weighted-average vesting periods of approximately 0.4 years.

The 2013 Plan provides for the issuance of RSUs to employees, directors, and consultants. RSUs issued under the 2013 Plan generally vest over four years. A summary of activity of RSUs under the 2013 Plan at December 31, 2022 and changes during the periods then ended is presented in the following table:


	Number of RSUs Outstanding (in thousands)	Weighted- Average Grant Date Fair Value Per Share		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2019	3,249	$	85.39	$	548,145
Granted	1,599	236.97
Released	(1,804)	99.31
Canceled/Forfeited	(319)	111.47
Outstanding at December 31, 2020	2,725	$	162.04	$	1,032,997
Granted	2,792	299.53
Released	(1,811)	185.55
Canceled/Forfeited	(855)	240.21
Outstanding at December 31, 2021	2,851	$	258.26	$	534,186
Granted	5,999	72.96
Released	(2,787)	131.18
Canceled/Forfeited	(963)	206.32
Outstanding at December 31, 2022	5,100	$	119.55	$	180,577

As of December 31, 2022 and 2021, there was a total of $422.3 million and $554.1 million of unrecognized share-based compensation expense, net of estimated forfeitures, related to RSUs, which will be recognized on a straight-line basis over the remaining weighted-average vesting periods of approximately 2.8 years.

The Company’s board of directors (the “Board”) adopted employee equity bonus plans (the “Bonus Plans”), which allow the recipients to earn fully vested shares of the Company’s Class A Common Stock upon the achievement of quarterly service and performance conditions. During the year ended December 31, 2022 and 2021, 813,330 and 173,441 RSUs were issued under the Company's Key Employee Equity Bonus Plan (“KEEB Plans”), respectively. The total requisite service period of each quarterly award is approximately 0.4 years.

The unrecognized share-based compensation expense as of December 31, 2022 was approximately $4.4 million, which will be recognized over the remaining service period of 0.1 years. The shares issued under the KEEB Plans will be issued from the reserve of shares available for issuance under the 2013 Plan.