Income taxes (Tables)

12 Months Ended

Dec. 31, 2014

Income taxes

Schedule of components of the Company's income (loss) before provision for income taxes by jurisdiction

	Year ended December 31,
	2014		2013			2012
United States	$	2,563,036	$	537,097		$	(6,307,445	)
Outside United States		1,397,812		(474,222	)		2,002,251
Income (loss) before provision for income taxes, net	$	3,960,848	$	62,875		$	(4,305,194	)

Schedule of components of the provision for income taxes

	Year ended December 31,
	2014		2013			2012
Current tax:
United States—Federal	$	—	$	—		$	—
United States—State and local		9,456		5,754			11,056
Outside United States		756,752		619,043			417,837
Total current tax		766,208		624,797			428,893
Deferred tax:
United States—Federal		—		—			—
United States—State and local		—		—			—
Outside United States		34,255		(583,928	)		(281,782	)
Total deferred tax		34,255		(583,928	)		(281,782	)
Provision for income taxes, net		800,463	$	40,869		$	147,111

Schedule of reconciliation from the U.S. Federal statutory income rate of 34.0% to the effective income tax rate

	Year ended December 31,
	2014			2013			2012
Federal statutory rate		34.0	%		34.0	%		34.0	%
State tax (less than 0.2% for 2012)		0.24			9.2			—
Permanent differences		2.49			54.3			(4.8	)
Foreign tax rates at rates different from U.S. rates		(22.06	)		(82.7	)		18.8
Valuation allowance		6.05			50.2			(51.4	)
Total tax provision		20.72	%		65.0	%		(3.4	)%

Schedule of components of deferred tax assets and liabilities

	As of December 31,
	2014			2013
Deferred tax assets:
Net operating loss carry-forwards	$	25,425,715		$	27,188,180
Stock options		3,482,800			3,514,890
Bonuses and salaries		26,993			33,111
Restricted stock		91,580			73,538
Provision for doubtful accounts		14,568			13,703
Foreign nonrefundable withholding tax		478,295			318,163
Foreign tax credit		335,698			—
Other		—			22,937
Total deferred tax assets		29,855,649			31,164,522
Less: Valuation allowance		(28,475,080	)		(29,416,464	)
Net deferred tax assets		1,380,569			1,748,058
Deferred tax liabilities:
Depreciation and amortization		(653,074	)		(981,816	)
Total deferred tax liabilities		(653,074	)		(981,816	)
Total deferred tax assets, net*	$	727,495		$	766,242

* As of December 31, 2014 and 2013, deferred tax assets, net, are included in the balance sheet classification "Security deposits and other assets."