Stockholders' Equity

6 Months Ended

Jun. 30, 2016

Stockholders' Equity Note [Abstract]

Stockholders' Equity

STOCKHOLDERS’ EQUITY

Warrants

A summary of warrant activity for the six months ended June 30, 2016 is presented as follows:

	Warrants Outstanding		Weighted Average Exercise Price During Period
Balance at December 31, 2015	14,250		$	4.30
Exercised	—		—
Canceled/forfeited	(7,500	)	4.30
Expired	—		—
Balance at June 30, 2016	6,750		$	4.30
Exercisable at June 30, 2016	—		$	—

Stock-based compensation

Stock-based compensation expense is attributable to stock options and restricted stock unit awards. For all stock-based awards, we recognize expense using a straight-line amortization method.

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

	Three months ended June 30,				Six months ended June 30,
	2016		2015		2016		2015
Cost of sales	$	10	$	15	$	24	$	18
Product development	20		13		36		16
Selling, general, and administrative	354		144		580		250
Total stock-based compensation	$	384	$	172	$	640	$	284

Total unearned stock-based compensation was $2.0 million at June 30, 2016, compared to $1.1 million at June 30, 2015. These costs will be charged to expense and amortized on a straight-line basis in subsequent periods. The weighted average period over which the unearned compensation at June 30, 2016 is expected to be recognized is approximately 2.1 years.

Stock options

The fair value of each stock option is estimated on the date of grant using the Black-Scholes option pricing model. 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:

	Six months ended June 30,
	2016			2015
Fair value of options issued	$	5.59		$	4.11
Exercise price	$	7.42		$	5.54
Expected life of option (in years)	5.8			5.8
Risk-free interest rate	1.6		%	1.7		%
Expected volatility	93.3		%	88.3		%
Dividend yield	0.0		%	0.0		%

A summary of option activity under all plans for the six months ended June 30, 2016 is presented as follows:

	Number of Options		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (in years)
Balance at December 31, 2015	602,207		$	8.58
Granted	123,790		7.42
Exercised	(68,307	)	4.59
Canceled/forfeited	(43,725	)	7.97
Expired	—		—
Balance at June 30, 2016	613,965		$	8.84	7.9
Vested and expected to vest at June 30, 2016	577,223		$	8.94	7.8
Exercisable at June 30, 2016	384,778		$	9.54	7.2

Restricted stock units

A summary of restricted stock unit activity under all plans for the six months ended June 30, 2016 is presented as follows:

	Restricted Stock Units		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Life (in years)
Balance at December 31, 2015	57,500		$	7.31
Granted	270,895		6.67
Released	(10,000	)	15.08
Canceled/forfeited	(45,770	)	6.84
Balance at June 30, 2016	272,625		$	6.47	2.0