Consolidated Statements of Comprehensive Loss (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Consolidated Statements of Comprehensive Loss
Revenues	$ 56,751	$ 37,547	$ 151,178	$ 93,813
Costs and operating expenses:
Cost of revenue (exclusive of depreciation and amortization presented separately below; includes related party expenses of $529 for the three months ended September 30, 2013, and $405 and $1,671 for nine months ended September 30, 2014 and 2013, respectively)	4,666	3,652	12,524	11,087
Sales and marketing (includes related party expenses of $6,700 and $2,302 for the three months ended September 30, 2014 and 2013, and $14,543 and $5,749 for nine months ended September 30, 2014 and 2013, respectively)	36,399	21,878	97,458	51,287
Technology and development	10,906	5,512	26,751	16,934
General and administrative	14,919	7,716	42,873	20,658
Depreciation and amortization	3,388	3,241	9,474	9,175
Total costs and operating expenses	70,278	41,999	189,080	109,141
Loss from operations	(13,527)	(4,452)	(37,902)	(15,328)
Interest income	14	30	41	91
Interest expense	(27)	(58)	(327)	(1,809)
Other income	20	5	30	19
Loss before provision for income taxes	(13,520)	(4,475)	(38,158)	(17,027)
Provision for income taxes	120	136	437	409
Net loss	(13,640)	(4,611)	(38,595)	(17,436)
Net loss per share
Basic and diluted	$ (0.18)	$ (0.08)	$ (0.56)	$ (0.30)
Weighted average common shares outstanding, basic and diluted	76,880	59,799	68,315	58,096
Other comprehensive loss:
Comprehensive loss	$ (13,640)	$ (4,611)	$ (38,595)	$ (17,436)