ComScore - July 2007

Through an extensive database system, comScore measures Internet media and website usage. Using a cross-section of more than 2 million consumers, comScore collects its data by capturing consumers' online and offline browsing behaviors and transactions. Participants also take part in research surveys that are designed to show their attitudes and intentions while browsing. By taking this approach, comScore can provide accurate behavioral research for marketers.

Hitwise - July 2007

Hitwise gathers data by providing Internet Service Providers (ISPs) software that analyzes website usage logs on their networks. The data sent by the software show page requests, visits and average visit length to websites. To create a clear picture of website usage, Hitwise combines this data with demographic and lifestyle information. The sample size from which Hitwise draws its information is made up of 25 million people worldwide, 10 million of whom are in the United States.

Neilsen//Netratings - May & June 2007

To provide an accurate representation of Internet searches, Nielsen//NetRatings combines site-centric and user-based services to analyze website usage. Their services implement user lifestyle and demographic data with several other factors, including online advertising intelligence, custom data, and research and analysis. All of this information is combined to gather the most precise data possible. Nielsen//NetRatings' thorough methods have helped establish them as a global leader in the Internet media and market research field.