CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Revenue	$ 92,642	$ 54,369	$ 167,039	$ 92,581
Cost of revenue	46,923	28,981	84,458	49,652
Gross profit	45,719	25,388	82,581	42,929
Operating expenses:
Research and development	8,434	3,711	15,675	6,123
Sales and marketing	33,789	18,419	63,548	34,649
General and administrative	12,135	5,775	22,475	10,952
Total operating expenses	54,358	27,905	101,698	51,724
Loss from operations	(8,639)	(2,517)	(19,117)	(8,795)
Other expense, net:
Interest expense	(514)	(229)	(928)	(353)
Other income (expense)—net	(425)	151	(444)	(368)
Change in fair value of convertible preferred stock warrant liability	0	(1,258)	0	(2,355)
Other expense, net	(939)	(1,336)	(1,372)	(3,076)
Loss before income taxes	(9,578)	(3,853)	(20,489)	(11,871)
Provision for income taxes	(181)	14	(496)	(40)
Net loss	$ (9,759)	$ (3,839)	$ (20,985)	$ (11,911)
Basic and diluted net loss per share attributable to common stockholders	$ (0.28)	$ (0.46)	$ (0.61)	$ (1.43)
Basic and diluted weighted-average shares used to compute net loss per share attributable to common stockholders	35,172	8,396	34,606	8,347