Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenue	$ 255,416	$ 174,478	$ 111,626
Cost of revenue	74,375	50,064	34,189
Gross profit	181,041	124,414	77,437
Operating expenses:
Research and development	22,909	18,196	17,090
Sales and marketing	125,458	83,579	63,185
General and administrative	28,980	20,515	16,510
Total operating expenses	177,347	122,290	96,785
Income (loss) from operations	3,694	2,124	(19,348)
Interest income, net	58	63	80
Other income (expense), net	(420)	(425)	103
Income (loss) before income taxes	3,332	1,762	(19,165)
Provision for (benefit from) income taxes	(38,470)	231	140
Net income (loss)	$ 41,802	$ 1,531	$ (19,305)
Basic net income (loss) per share:
Net income (loss) per share, basic (dollars per share)	$ 1.08	$ 0.04	$ (0.53)
Weighted average shares of common stock outstanding used in computing net income (loss) per share, basic (shares)	38,754,643	37,563,590	36,209,051
Diluted net income (loss) per share:
Net income (loss) per share, diluted (dollars per share)	$ 1.02	$ 0.04	$ (0.53)
Weighted average shares of common stock outstanding used in computing net income (loss) per share, diluted (shares)	40,795,646	40,996,972	36,209,051