Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of Property and Equipment

Property and equipment as of December 31, 2012, and 2011 consisted of the following (in thousands):

	2012			2011
Purchased and internally developed software	$	83,239		$	73,561
Portable People Meter equipment		45,570			49,601
Computer equipment		23,793			21,776
Leasehold improvements		18,780			17,833
Machinery, furniture and fixtures		9,218			8,598
		180,600			171,369
Accumulated depreciation and amortization		(118,931	)		(100,718	)
Property and equipment, net	$	61,669		$	70,651

Schedule of Property and Equipment Additional Information

	For the Years Ended December 31,
Additional Information	2012		2011		2010
Depreciation and Amortization of Property and Equipment:
Cost of revenue	$	25,332	$	26,319	$	24,778
Selling, general, and administrative		2,634		1,748		1,628
Research and development		344		475		280
Total depreciation and amortization expense	$	28,310	$	28,542	$	26,686
Impairment charges associated with property and equipment and recognized in selling, general, and administrative expense	$	909	$	162	$	628
Loss on asset disposals	$	2,082	$	1,961	$	2,383
Interest capitalized during the year	$	—	$	39	$	34