The precision and representivity of the comScore panel has been validated by several leading industry bodies and the use of independent third-party data sources. Though comScore is confident in its application and use of rigorous statistical methods, we recognize the value in having our data and related methodologies validated by impartial third parties.

One important validation was provided by The Advertising Research Foundation (ARF), which has conducted a thorough evaluation of the comScore methodology.

comScore is undergoing an MRC audit of the U.S. Media Metrix, Video Metrix, and comScore Direct services. Three phases of the Media Metrix audit - the meter technology (2007), our enumeration study to develop Internet universe estimates (2009), and our panel recruitment and maintenance (2009) – have already been completed. The audit will continue throughout 2010, focusing on the final phases: the calibration panel and back-end data processing. We expect to complete the comScore Direct auditing by the end of June, 2010.

Another important validation of the comScore panel is through the use of the U.S. Department of Commerce quarterly estimate of e-commerce sales. comScore releases its quarterly e-commerce data approximately two weeks following the end of the quarter and several weeks prior to the release of the Department of Commerce estimate. Since comScore began releasing e-commerce data in 2001, our estimates have closely matched the Department of Commerce sales data, typically within a range of 2-3%.