Equity and Employee Stock Plans

Common Stock—At March 31, 2019 and December 31, 2018, the Company was authorized to issue 500,000,000 shares of common stock with a par value of $0.001 per share.

2017 Equity Incentive Plan—The Company's 2017 Equity Incentive Plan ("2017 EIP") became effective on July 26, 2017, and provides for the issuance of incentive and nonqualified common stock options and restricted stock units to employees, directors, officers, and consultants of the Company. The number of shares of common stock initially reserved for issuance under the 2017 EIP was 7,898,159. The number of shares reserved for issuance under the 2017 EIP will increase automatically on January 1 of each calendar year beginning on January 1, 2018, and continuing through January 1, 2028, by the number of shares equal to the lesser of 5% of the total outstanding shares of the Company's common stock as of the immediately preceding December 31 or an amount determined by the board of directors.

Amended and Restated 2004 Equity Incentive Plan-The Company granted options under its 2004 Equity Incentive Plan, as amended ("2004 Plan"), until July 26, 2017, when the plan was terminated in connection with the Company’s IPO. Accordingly, no shares are available for future issuance under this plan. The 2004 Plan continues to govern outstanding equity awards granted thereunder.

2017 Employee Stock Purchase Plan—The Company initially reserved 1,600,000 shares of common stock for issuance under the 2017 Employee Stock Purchase Plan (the "2017 ESPP"). The number of shares reserved for issuance under the 2017 ESPP will increase automatically on January 1 of each calendar year beginning after the first offering date and continuing through January 1, 2028, by the number of shares equal to the lesser of 1% of the total outstanding shares of the Company’s common stock as of the immediately preceding December 31 or an amount determined by the board of directors.

The Company has reserved shares of common stock, on an as-converted basis, for future issuance as follows:



	March 31, 2019	December 31, 2018
Equity Incentive Plans
Stock options outstanding	8,713,162	9,435,349
Restricted stock units outstanding	3,588,275	3,264,702
Shares available for future equity grants	9,199,286	5,068,013
Total	21,500,723	17,768,064
2017 Employee Stock Purchase Plan
Shares available for purchase on January 1, 2019 and 2018, respectively	2,890,973	2,414,688
Shares issued since January 1, 2019 and 2018, respectively	—	425,228
Total shares available for future purchases	2,890,973	1,989,460

Preferred Stock—As of March 31, 2019 and December 31, 2018, the Company was authorized to issue 10,000,000 shares of preferred stock with a par value of $0.001, of which no shares were issued and outstanding.

Stock Options—The following table summarizes activity for stock options for the three months ended March 31, 2019:



	Number Of Options	Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Life (years)	Aggregate Intrinsic Value
Outstanding at December 31, 2018	9,435,349	$	6.48	6.06	$	74,669
Options exercised	(679,495)	5.49
Options forfeited	(40,550)	9.15
Options canceled	(2,142)	8.35
Outstanding at March 31, 2019	8,713,162	6.55		6.00	119,575
Options exercisable at March 31, 2019	7,258,130	$	6.01	5.69	$	103,486

The grant date fair value of options to purchase common stock is recorded as stock-based compensation over the vesting period. As of March 31, 2019, there was $6,174 of total unrecognized compensation cost related to options to purchase common stock, which is expected to be recognized over a weighted-average period of 1.40 years.

Restricted Stock Units—The following table summarizes activity for restricted stock units for the three months ended March 31, 2019:



	Restricted Stock Units		Weighted Average Grant-Date Fair Value
Unvested outstanding at December 31, 2018	3,264,702		$	19.68
Granted	569,915		19.61
Vested	(139,889	)	20.99
Forfeited or canceled	(106,453	)	19.48
Unvested outstanding at March 31, 2019	3,588,275		$	19.62

The grant date fair value of restricted stock units is recorded as stock-based compensation over the vesting period. As of March 31, 2019, there was $64,843 of total unrecognized compensation cost related to restricted stock units, which is expected to be recognized over a weighted-average period of 3.29 years.

During the three months ended March 31, 2019, the Company granted no restricted stock units subject to performance conditions. As of March 31, 2019, there were outstanding 134,602 restricted stock units subject to performance conditions (the "2018 Performance RSUs") at 100% of the target level. For the three months ended March 31, 2019, $278 of share-based compensation expense was recognized for the 2018 Performance RSUs.

Compensation Cost—The following table presents detail of stock-based compensation, net of the amount capitalized in internally developed software, included in the Company’s condensed consolidated statements of operations for the periods indicated below



	Three Months Ended March 31,
	2019		2018
Cost of revenue	$	1,465	$	1,300
Technology and development	2,656		1,473
Marketing	286		119
General and administrative	1,999		1,304
Total stock-based compensation	$	6,406	$	4,196