Condensed Consolidated Statements of Comprehensive Loss (unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Revenues		$ 26,284	$ 19,158	$ 50,441	$ 35,992
Cost of revenues	[1]	14,138	10,830	27,410	21,042
Gross profit		12,146	8,328	23,031	14,950
Operating expenses:
Sales and marketing	[1]	6,987	6,032	13,181	11,541
Research and development	[1]	4,797	2,787	8,948	5,523
General and administrative	[1]	5,344	4,058	10,469	7,776
Total operating expenses		17,128	12,877	32,598	24,840
Loss from operations		(4,982)	(4,549)	(9,567)	(9,890)
Other income (expense):
Interest and other income		77	5	121	5
Interest and other expense		(65)	(124)	(137)	(331)
Total other income (expense), net		12	(119)	(16)	(326)
Loss before income taxes		(4,970)	(4,668)	(9,583)	(10,216)
Provision for income taxes		(12)	(15)	(44)	(33)
Net loss		(4,982)	(4,683)	(9,627)	(10,249)
Other comprehensive loss:
Unrealized loss on available-for-sale investments		(45)	0	(36)	0
Comprehensive loss		$ (5,027)	$ (4,683)	$ (9,663)	$ (10,249)
Net loss per common share:
Net loss per common share, basic and diluted		$ (0.13)	$ (0.14)	$ (0.26)	$ (0.42)
Weighted average common shares outstanding:
Basic and diluted (shares)		37,232	34,068	36,437	24,143

[1] Includes stock-based compensation as follows for the three and six months ended June 30, 2015 and 2014, respectively, Cost of Revenues of $238, $416, $147, and $273, respectively; Sales and Marketing of $344, $636, $187 and $354, respectively; Research and Development of $217, $379, $122, and $229, respectively; General and Administrative of $840, $1,530, $612 and $1,130, respectively; Total stock-based compensation of $1,639, $2,961, $1,068 and $1,986, respectively.