Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2015

Stockholders' Equity Note [Abstract]

A summary of warrant activity for the nine months ended September 30, 2015 is presented as follows:



	Warrants Outstanding		Weighted Average Exercise Price During Period
Balance at December 31, 2014	969,549		$	4.61
Exercised	(638,189	)	4.58
Canceled/forfeited	(112,110	)	5.54
Expired	(205,000	)	4.20
Balance at September 30, 2015	14,250		$	4.30

Exercisable at September 30, 2015	—		$	—

Summary of stock-based compensation expense

The following table summarizes stock-based compensation expense and the impact it had on operations for the periods presented (in thousands):



	Three months ended September 30,				Nine months ended September 30,
	2015		2014		2015		2014
Cost of sales	$	11	$	4	$	29	$	8
Product development	10		3		26		5
Selling, general, and administrative	294		140		544		380
Total stock-based compensation	$	315	$	147	$	599	$	393

Schedule of valuation assumptions

Estimates utilized in the calculation include the expected life of the option, risk-free interest rate, and expected volatility, and are further comparatively detailed as follows:



	Nine months ended September 30,
	2015			2014
Fair value of options issued	$	5.18		$	3.44
Exercise price	$	7.04		$	4.48
Expected life of option (in years)	5.8			5.6
Risk-free interest rate	1.7		%	1.8		%
Expected volatility	90.7		%	97.9		%
Dividend yield	0.0		%	0.0		%

Summary of option activity

A summary of option activity under all plans for the nine months ended September 30, 2015 is presented as follows:



	Number of Option		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (in years)
Balance at December 31, 2014	459,271		$	8.95
Granted	326,000		8.35
Exercised	(45,361	)	4.63
Canceled/forfeited	(105,565	)	6.26
Expired	(5,900	)	96.00
Balance at September 30, 2015	628,445		$	8.58	8.4

Vested and expected to vest at September 30, 2015	575,974		$	8.71	8.3

Exercisable at September 30, 2015	282,583		$	9.18	7.2

Restricted stock units

A summary of restricted stock unit activity under all plans for the nine months ended September 30, 2015 is presented as follows:



	Restricted Stock Units		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Life (in years)
Balance at December 31, 2014	—		$	—
Granted	72,750		6.82
Canceled/forfeited	(14,250	)	5.55
Balance at September 30, 2015	58,500		$	7.13	1.1

- Definition

Tabular disclosure of warrants or rights issued. Warrants and rights outstanding are derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. Warrants are often included in a new debt issue to entice investors by a higher return potential. The main difference between warrants and call options is that warrants are issued and guaranteed by the company, whereas options are exchange instruments and are not issued by the company. Also, the lifetime of a warrant is often measured in years, while the lifetime of a typical option is measured in months. Disclose the title of issue of securities called for by warrants and rights outstanding, the aggregate amount of securities called for by warrants and rights outstanding, the date from which the warrants or rights are exercisable, and the price at which the warrant or right is exercisable.

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