8.	Arbitron Mobile Contingent Consideration

On July 28, 2011, a wholly-owned subsidiary of the Company acquired Zokem Oy, which is now being consolidated as Arbitron Mobile. The purchase price was $10.6 million in cash plus a contingent consideration arrangement. The contingent consideration arrangement provides for possible additional cash payments to be made by the Company to the former Zokem Oy shareholders through 2015 of up to $12.0 million, which are contingent upon Arbitron Mobile reaching certain financial performance targets in the future. The Company periodically reassesses the fair value of the contingent consideration by applying the income approach method. The key assumptions used in the fair value valuation include a probability-weighted range of performance targets for the four-year measurement period of 2012 through 2015 and an adjusted discount rate. As of both March 31, 2013 and December 31, 2012, the Company’s fair value estimate of the contingent consideration was $0.6 million, which is recorded as a portion of noncurrent liabilities on the Company’s consolidated balance sheet.