Income Taxes (Tables)

6 Months Ended

Jun. 30, 2012

Income Tax Disclosure [Abstract]

Components of income (loss) before income tax

The components of income (loss) before income taxes are as follows:

	Years ended December 31,
(in thousands)	2009			2010			2011
United States	$	(992	)	$	921		$	(2,421	)
International	—			(78		)	227
Total income (loss) before income taxes	$	(992	)	$	843		$	(2,194	)

Components of the provision (benefit) for income taxes

The components of the provision (benefit) for income taxes are as follows:

	Years ended December 31,
(in thousands)	2009	2010			2011
Current
Federal	—	$	(26	)	$	25
State	—	83			156
Foreign	—	9			55
	—	66			236
Deferred
Federal	—	(310		)	60
State	—	(96		)	9
Foreign	—	(27		)	(20		)
	—	(433		)	49
Total income tax provision (benefit)	—	$	(367	)	$	285

Reconciliation of the provision for income taxes at the statutory rate

Reconciliation of the provision for income taxes at the statutory rate to the Company’s provision for income tax is as follows:

	Years ended December 31,
(in thousands)	2009			2010			2011
U.S. federal taxes (benefit) at statutory rate	$	(332	)	$	316		$	(746	)
State income taxes, net of federal benefit	183			3			109
Foreign income taxes at rates other than the US rate	(4		)	2			(72		)
Stock-based compensation	167			229			340
Change in valuation allowance	(230		)	(1,168		)	546
Non-deductible warrant expense	80			110			334
Non-deductible acquisition costs	—			283			—
Research and development credits	94			(174		)	(290		)
Other	42			32			64
Total	—			$	(367	)	$	285

Deferred tax assets and liabilities

The following table presents the significant components of the Company’s deferred tax assets and liabilities for the periods presented:

	As of December 31,						As of June 30,
(in thousands)	2010			2011			2012
							(unaudited)
Deferred tax assets
Net operating loss carryforward	$	18,659		$	17,775		$	15,841
Research and development credits	1,982			2,365			2,475
Depreciation and amortization	364			55			58
Reserves and accruals	1,648			3,229			3,883
Total deferred tax assets	22,653			23,424			22,257
Valuation allowance	(21,588		)	(22,687		)	(21,729		)
Net deferred tax assets	1,065			737			528
Deferred tax liabilities	(1,103		)	(824		)	(644		)
Net deferred tax liabilities	$	(38	)	$	(87	)	$	(116	)

Changes in the unrecognized tax benefits

The following table reflects changes in the unrecognized tax benefits since January 1, 2010:

	Years ended   December 31,
(in thousands)	2010			2011
Gross amount of unrecognized tax benefits as of the beginning of the period	$	539		$	675
Increases related to prior year tax provisions	—			—
Decreases related to prior year tax provisions	(3		)	(1		)
Increases related to current year tax provisions	139			234
Gross amount of unrecognized tax benefits as of the end of the period	$	675		$	908