Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Condensed Consolidated Statements of Operations [Abstract]
Net revenue	$ 59,090	$ 50,088	$ 176,358	$ 144,722
Cost of revenue	34,544	28,034	101,002	82,399
Gross profit	24,546	22,054	75,356	62,323
Operating expenses:
Sales and marketing	13,512	12,144	41,158	34,664
Research and development	4,416	3,547	13,295	9,650
General and administrative	10,000	8,969	30,639	24,692
Total operating expenses	27,928	24,660	85,092	69,006
Loss from operations	(3,382)	(2,606)	(9,736)	(6,683)
Interest expense	(70)	(27)	(180)	(349)
Other income (expense), net	190	309	(124)	(662)
Loss before income taxes	(3,262)	(2,324)	(10,040)	(7,694)
Income tax (benefit) provision	322	501	31,589	(21,152)
Net income (loss)	$ (3,584)	$ (2,825)	$ (41,629)	$ 13,458
Net income (loss) per common share:
Basic	$ (0.05)	$ (0.04)	$ (0.56)	$ 0.21
Diluted	$ (0.05)	$ (0.04)	$ (0.56)	$ 0.19
Weighted-average shares used in computing net income (loss) per common share:
Basic	74,667	69,464	73,994	64,989
Diluted	74,667	69,464	73,994	72,208