Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenues	$ 13,737	$ 10,491	$ 37,141	$ 28,325
Cost of revenues	3,034	2,636	8,736	6,675
Gross Profit	10,703	7,855	28,405	21,650
Operating expenses:
Sales and marketing	9,672	6,566	27,616	19,272
General and administrative	3,238	2,256	8,952	5,735
Research and development	2,125	1,843	6,010	6,018
Total operating expenses	15,035	10,665	42,578	31,025
Loss from Operations	(4,332)	(2,810)	(14,173)	(9,375)
Other (income) expense:
Interest expense	928	807	2,749	2,068
Other expense (income), net	(299)	136	1,032	(308)
Net Loss	$ (4,961)	$ (3,753)	$ (17,954)	$ (11,135)
Net loss per share of common stock outstanding, basic and diluted	$ (0.29)	$ (19.35)	$ (2.99)	$ (62.56)
Weighted-average common shares outstanding, basic and diluted	17,382	194	6,014	178