Consolidated Statements of Cash Flows - USD ($)		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income		$ 25,072,002	$ 10,362,448	$ 3,160,385
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense		1,820,404	1,811,156	1,263,660
Depreciation and amortization expense		2,657,255	3,099,990	3,016,783
Provision for doubtful accounts		62,681	8,388	46,652
Deferred tax benefit		(16,466,893)	(5,478,818)
Loss on disposal of property and equipment		500
Changes in operating assets and liabilities:
Decrease (increase) in settlement assets		91,162	(957,909)	1,055,984
Decrease (increase) in accounts receivables, prepaid expenses and other current assets		330,610	346,422	(743,358)
Decrease (increase) in other long-term assets		529,213	911,138	(62,992)
(Decrease) increase in accounts payable and accrued expenses		(2,678,860)	1,292,718	(2,005,464)
(Decrease) increase in due to merchants		(63,524)	963,550	(419,222)
Other		(130,611)	(172,661)	(66,529)
Net cash provided by operating activities		11,223,939	12,186,422	5,245,899
Cash flows from investing activities:
Increase in restricted cash		(20,972)	(44,501)	(1,738,571)
Increase (decrease) in merchant reserves		22,487	(75,322)	1,752,521
Purchase of property and equipment		(437,308)	(183,090)	(117,412)
Capitalized software development		(1,294,129)	(1,102,765)	(1,292,314)
Purchase of intangible assets		(16,300)	(20,979)	(125,980)
Net cash used for investing activities		(1,746,222)	(1,426,657)	(1,521,756)
Cash flows from financing activities:
Proceeds from exercise of stock options		3,420,957	1,657,591	934,032
Principal payments on capital lease obligations		(340,899)	(519,223)	(570,249)
Borrowings under credit facility		13,916,000
Repayments under credit facility		(4,000,000)
Purchase of treasury stock		(23,843,474)	(7,060,409)	(822,603)
Net cash used for financing activities		(10,847,416)	(5,922,041)	(458,820)
Effect of exchange rate changes on cash and cash equivalents	[1]	0	0	0
Net (decrease) increase in cash and cash equivalents		(1,369,699)	4,837,724	3,265,323
Cash and cash equivalents at beginning of period		14,675,515	9,837,791	6,572,468
Cash and cash equivalents at end of period		13,305,816	14,675,515	9,837,791
Cash paid for:
Interest		247,138	33,499	64,585
Income taxes		1,027,864	765,380	765,807
Non-cash investing and financing activities:
Common stock issued for preferred stock conversion		21,629
Common stock issued for stock options exercised		152	184	1,390
Assets acquired under capital leases		122,630	156,129	429,611
Accrued capitalized hardware, software and fixed assets		307,660	57,163	74,017
Capitalized stock-based compensation		$ 27,703	$ 33,001	$ 52,473

[1] For the years ended December 31, 2016, 2015 and 2014, the effect of exchange rate changes on cash and cash equivalents was immaterial.