Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenues	$ 17,092,336	$ 12,027,528
Cost of revenues	10,235,538	7,113,005
Gross profit	6,856,798	4,914,523
Operating expenses:
Research and development	3,497,636	4,394,353
Sales and marketing	10,751,863	10,855,445
General and administrative	5,689,917	4,872,670
Total operating expenses	19,939,416	20,122,468
Loss from operations	(13,082,618)	(15,207,945)
Interest income	14,885	19,132
Change in fair value of warrant liability	208,480	275,662
Net loss	(12,859,253)	(14,913,151)
Net loss applicable to common stockholders:
Deemed dividends attributable to preferred shareholders (Note 12)	(6,874,780)	(19,846,377)
Net loss applicable to common stockholders	$ (19,734,033)	$ (34,759,528)
Net loss per common share applicable to common stockholders, basic and diluted (in dollars per share)	$ (11.60)	$ (58.21)
Weighted average number of common shares outstanding, basic and diluted (in shares)	1,701,481	597,130