Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues [Abstract]
Revenues	$ 27,749	$ 23,382	$ 78,923	$ 66,763
Cost of revenues	6,415	4,634	18,134	13,423
Gross profit	21,334	18,748	60,789	53,340
Operating expenses:
Research and development	5,151	5,076	15,739	15,325
Sales and marketing	10,411	8,797	30,739	27,827
General and administrative	4,277	3,154	12,226	8,811
Total operating expenses	19,839	17,027	58,704	51,963
Income from operations	1,495	1,721	2,085	1,377
Other income (expense), net:
Interest expense	(7)	(38)	(37)	(153)
Interest income	115	1	273	2
Other income (expense), net	(84)	60	(370)	(44)
Total other income (expense), net	24	23	(134)	(195)
Income before provision for income taxes	1,519	1,744	1,951	1,182
Provision for income taxes	210	77	372	77
Net income	1,309	1,667	1,579	1,105
Net income attributable to common stockholders	$ 1,307	$ 415	$ 1,577	$ 264
Net income per share attributable to common stockholders:
Basic (USD per share)	$ 0.04	$ 0.07	$ 0.05	$ 0.05
Diluted (USD per share)	$ 0.04	$ 0.06	$ 0.04	$ 0.04
Weighted average shares used in computing net income per share attributable to common stockholders:
Basic (shares)	32,088	5,843	31,789	5,540
Diluted (shares)	36,247	26,545	35,704	25,972