Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2014

Schedule of computation of basic and diluted net income (loss) per share

	Year ended December 31,
	2014			2013			2012
Numerator:
Net income (loss)	$	3,160,385		$	22,006		$	(4,452,305	)
Amounts allocated to participating preferred stockholders under the two-class method		(357,248	)		(2,507	)		—
Net income (loss) applicable to common stockholders (basic and dilutive)	$	2,803,137		$	19,499		$	(4,452,305	)
Denominator:
Weighted average common stock outstanding (basic)		53,494,952			52,943,203			52,187,144
Common equivalent shares from options and warrants to purchase common stock		1,138,229			1,522,082			—
Weighted average common stock outstanding (diluted)(1)		54,633,181			54,465,285			52,187,144
Basic net income (loss) per share applicable to common stockholders	$	0.05		$	0.00		$	(0.09	)
Diluted net income (loss) per share applicable to common stockholders(1)	$	0.05		$	0.00		$	(0.09	)

(1) In accordance with ASC 260-10-45-48 for the year ended December 31, 2014, 2013 and 2012, the Company has excluded 1.3 million, 1.6 million and 0.9 million, respectively, contingently issued restricted shares from diluted weighted average common stock outstanding as the contingencies (a) were not satisfied at the reporting date nor (b) would have been satisfied if the reporting date was at the end of the contingency period.

Schedule of weighted average securities outstanding that have been excluded from the diluted net income (loss) per share calculation because the effect would have been anti-dilutive

	Year ended December 31,
	2014		2013		2012
Stock options		5,107,474		2,458,471		8,528,816
Restricted stock awards		90,467		—		—
Warrants		68,304		85,629		2,055,722
Convertible preferred stock(1)		6,851,144		6,851,144		6,851,144
Total antidilutive securities		12,117,389		9,395,244		17,435,682

(1) Diluted net income per share increases when convertible preferred stock are included in the required sequence in the diluted earnings per share computation. As such convertible preferred stock are excluded from the computation of diluted earnings per share for the years ended December 31, 2014, 2013 and 2012.

Summary of stock-based compensation expense recognized by income statement classification

	Year ended December 31,
	2014		2013		2012
Processing and service costs	$	259,663	$	238,101	$	262,775
Selling, general and administrative expenses		849,640		989,268		872,272
Restructuring charges		154,357		—		—
Total stock-based compensation expense	$	1,263,660	$	1,227,369	$	1,135,047

Summary of stock-based compensation expense recognized by type

	Year ended December 31,
	2014		2013		2012
Stock options	$	850,727	$	983,810	$	1,135,047
Restricted stock awards		412,933		243,559		—
Warrants		—		—		—
Total stock-based compensation expense	$	1,263,660	$	1,227,369	$	1,135,047

Summary of the unamortized stock-based compensation expense and associated weighted average remaining amortization periods

	As of December 31, 2014				As of December 31, 2013
	Unamortized stock-based compensation expense		Weighted average remaining amortization period (in years)		Unamortized stock-based compensation expense		Weighted average remaining amortization period (in years)
Stock options	$	813,461		1.85	$	1,263,133		1.79
Restricted stock awards		424,795		1.49		1,624,187		2.05

Schedule of valuation assumptions used for the estimated fair market value of each stock based award granted on the grant date using the Black-Scholes Option Pricing Model

	Year ended December 31,
	2014	2013	2012
Expected life (in years)	5.88 - 6.02	5.51 - 5.98	5.25 - 6.00
Expected volatility (percentage)	38.48 - 41.98	40.74 - 42.41	45.13 - 47.36
Risk-free interest rate (percentage)	1.77 - 2.02	0.94 - 1.77	0.91 - 1.39
Expected dividend yield	—	—	—

Schedule of valuation assumptions used for estimated fair value of the market condition award on the grant date using a binomial lattice-based valuation pricing model

	July 26, 2011
Expected life (in years)		5.3
Expected volatility (percentage)		31.68
Risk-free interest rate (percentage)		2.04
Expected dividend yield		—

	November 15, 2013		March 10, 2014
Expected life (in years)		1.37		1.22
Expected volatility (percentage)		27.30		27.50
Risk-free interest rate (percentage)		0.23		0.23
Expected dividend yield		—		—

	June 27, 2014		August 15, 2014
Expected life (in years)		1.51		1.38
Expected volatility (percentage)		26.72		26.54
Risk-free interest rate (percentage)		0.17		0.25
Expected dividend yield		—		—

Accounts Receivable

Schedule of concentrations of 10% and greater

	As of December 31,
	2014			2013
Customer A		28	%		22	%
Customer B		13				***
Customer C		17			13
Customer D*		**			12

*	Customer D is a sponsoring bank for certain merchants within the Company's payment processing services. Customer D serves as an aggregator of merchant transactions and therefore, there is a concentration risk relating to receivables. However, revenues are generated from individual merchants that individually do not exceed 10% of the Company's revenue.
**	Less than 10% accounts receivable concentration.
***	New customer during 2014.

Revenue

Schedule of concentrations of 10% and greater

	Year ended December 31,
	2014			2013			2012
Customer A		21	%		21	%		23	%
Customer C		*			12			17

* Less than 10% revenue concentration.