Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenue	$ 101,369	$ 70,010	$ 48,687
Cost of revenue	37,190	30,004	21,890
Gross profit	64,179	40,006	26,797
Operating expenses:
Sales and marketing	46,345	30,922	20,957
Research and development	23,057	16,167	10,517
General and administrative	29,530	18,422	10,730
Change in fair value of contingent consideration	(11)	(1,434)	428
Total operating expenses	98,921	64,077	42,632
Loss from operations	(34,742)	(24,071)	(15,835)
Change in fair value of preferred stock warrant	(25)	(283)	(302)
Interest income	12
Interest expense	(955)	(68)	(21)
Other income (expense), net	(132)	(68)	(26)
Loss before provision for income taxes	(35,842)	(24,490)	(16,184)
Provision for income taxes	246	116	63
Net loss	(36,088)	(24,606)	(16,247)
Accretion of redeemable convertible preferred stock	(9,862)	(21,311)	(27,892)
Deemed dividend—preferred stock modification	1,748
Net loss attributable to common stockholders	$ (44,202)	$ (45,917)	$ (44,139)
Net loss per share attributable to common stockholders, basic and diluted	$ (1.68)	$ (4.17)	$ (4.10)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted	26,319,903	11,013,658	10,757,938