Note 4—Product Revenue

The Company differentiates revenue and cost of revenue dependent upon whether the source of revenue is related to Products, Rentals or Services (in thousands):


	Year ended December 31,
	2011		2010		2009
Revenue:
Product	$	176,245	$	93,763	$	72,282
Rental		63,610		42,169		28,620
Service		18,930		11,050		11,648

	$	258,785	$	146,982	$	112,550

Cost of revenue:
Product	$	109,115	$	54,924	$	48,728
Rental		27,581		22,390		17,769
Service		10,147		7,476		7,409
Depreciation		6,122		9,222		9,260

	$	152,965	$	94,012	$	83,166