Stock-based Awards (Tables)

9 Months Ended

Sep. 30, 2014

Stock-based Awards

Summary of stock option activity

				Weighted-
		Weighted-		Average
		Average		Remaining
	Number of	Exercise		Contract Life
	Options	Price		(in years)
Outstanding at December 31, 2013	18,363,144	$	4.89	7.17
Granted	10,746,379	$	15.84
Exercised	(1,878,681)	$	1.07
Canceled/forfeited	(802,368)	$	9.38
Outstanding at September 30, 2014	26,428,474	$	9.48	7.75
Vested and expected to vest at September 30, 2014	25,379,923	$	9.43	7.69
Exercisable at September 30, 2014	18,469,792	$	8.88	7.16

Summary of restricted stock unit activity

		Weighted-
		Average
	Number of	Grant Date
	Shares	Fair Value
Non-vested — December 31, 2013	—	$	—
Granted	747,112	$	10.52
Vested	(3,951)	$	23.47
Canceled/forfeited	(34,370)	$	10.31
Non-vested — September 30, 2014	708,791	$	10.25

Stock-based compensation cost categories

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2014		2013		2014		2013
Cost of revenue	$	134	$	28	$	297	$	81
Sales and marketing		1,413		591		3,757		1,696
Technology and development		2,069		362		3,933		1,143
General and administrative		5,824		987		12,991		2,664
Total stock-based compensation expense		9,440		1,968		20,978		5,584
Amount capitalized to internal software use		331		112		947		366
Total stock-based compensation cost	$	9,771	$	2,080	$	21,925	$	5,950