CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Income Statement [Abstract]
Revenue	$ 42,496	$ 36,759
Operating expenses:
Cost of revenue	10,134	7,923
Product development	8,021	6,657
Sales and marketing	14,478	11,089
General and administrative	10,238	6,125
Amortization of intangibles	224	77
Total operating expenses	43,095	31,871
(Loss) income from operations	(599)	4,888
Other income:
Financial income	26	331
Interest income	8	16
Total other income, net	34	347
(Loss) income before (benefit from) provision for income taxes	(565)	5,235
(Benefit from) provision for income taxes	(333)	2,112
Net (loss) income	$ (232)	$ 3,123
Basic net (loss) income per common share	$ 0.00	$ 0.06
Diluted net (loss) income per common share	$ 0.00	$ 0.06
Weighted average shares outstanding used in basic net (loss) income per common share calculation	55,864,045	54,419,498
Weighted average shares outstanding used in diluted net (loss) income per common share calculation	55,864,045	56,389,729