CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS
Revenue	$ 12,335	$ 9,838	$ 35,461	$ 25,991
Operating expenses:
Cost of revenue	5,618	4,168	15,322	11,741
Research and development	3,563	2,233	9,453	6,602
Selling and marketing	6,048	5,533	18,606	14,970
General and administrative	5,728	5,715	17,062	13,625
Intangible asset amortization	266		533
Total operating expenses	21,223	17,649	60,976	46,938
Loss from operations	(8,888)	(7,811)	(25,515)	(20,947)
Interest expense	(92)	(114)	(269)	(338)
Other income, net	35	23	93	54
Net loss	(8,945)	(7,902)	(25,691)	(21,231)
Comprehensive loss	$ (8,945)	$ (7,902)	$ (25,691)	$ (21,231)
Net loss per common share, basic and diluted (in dollars per share)	$ (0.32)	$ (0.37)	$ (1.01)	$ (0.99)
Shares use to compute net loss per common share, basic and diluted (in shares)	27,640,806	21,648,660	25,428,506	21,346,565