Several ways of identifying users and collecting demographic information and market information are disclosed, including branding a browser with a unique identification in each user request, identifying a user by his key strokes or mouse clicks, gathering demographic information using multiple data sets and by monitoring network traffic. Additionally, user requested content is distinguished from other, non-user content, and the performance of a server can be monitor and analyzed from a client a client perspective. Further, an Internet user's Internet data is routed to a known domain on the Internet, from which it is routed on to the intended recipient. The domain includes proxy servers which proxy the user's data requests to the domain, and database servers, which filter and build a database of the user's Internet usage. Particular data concerning certain behaviors of interest, such as purchasing data, is filtered into the database, and can form the basis for numerous market measures.