Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Revenue	$ 40,669,695	$ 33,796,581	$ 78,106,252	$ 66,484,512
Cost of revenue	4,775,820	3,424,728	9,184,501	6,842,046
Gross profit	35,893,875	30,371,853	68,921,751	59,642,466
Operating expenses
Research and development	6,917,933	6,696,432	14,308,957	12,916,403
Sales and marketing	22,566,866	16,474,132	43,134,733	33,319,955
General and administrative	6,351,845	4,799,987	17,872,172	9,705,251
Amortization of acquired intangibles	180,254	145,680	359,380	272,945
Total operating expenses	36,016,898	28,116,231	75,675,242	56,214,554
Income (loss) from operations	(123,023)	2,255,622	(6,753,491)	3,427,912
Interest income, net	155,254	217,977	320,342	433,467
Other (expense) income	(198,199)	(269,325)	453,921	(505,590)
Income (loss) before income taxes	(165,968)	2,204,274	(5,979,228)	3,355,789
Provision for income taxes	(1,193,973)	(1,628,597)	(1,187,368)	(2,703,872)
Net income (loss)	$ (1,359,941)	$ 575,677	$ (7,166,596)	$ 651,917
Net income (loss) per share:
Basic	$ (0.06)	$ 0.02	$ (0.29)	$ 0.03
Diluted	$ (0.06)	$ 0.02	$ (0.29)	$ 0.03
Weighted average shares outstanding:
Basic	24,262,417	24,677,893	24,485,429	24,625,851
Diluted	24,262,417	25,367,227	24,485,429	25,360,950