Property and equipment

12 Months Ended

Dec. 31, 2013

Property and equipment

Property and equipment

4. Property and equipment

        Property and equipment, net consist of the following:

			As of December 31,
	Estimated useful life (in years)
			2013			2012
Equipment		2 - 5	$	939,129		$	923,356
Computer hardware		3 - 5		2,493,658			1,688,262
Furniture and fixtures		5 - 7		182,562			72,155
Leasehold improvements		5 - 9		689,648			263,691
Total property and equipment, gross				4,304,997			2,947,464
Less: Accumulated depreciation and amortization				(2,106,357	)		(1,551,310	)
Total property and equipment, net			$	2,198,640		$	1,396,154

        Property and equipment depreciation and amortization expense is as follows:

	Year ended December 31,
	2013		2012		2011
Depreciation and amortization expense	$	554,765	$	532,784	$	656,837