A website server computer hosting a website can identify a visitor to the website by using information provided by a visitor server computer that interacts with the visitor. The information provided by the server computer, in some embodiments, can be a combination of an IP address and characteristics of a computing device from where the visitor visits the website. In some embodiments, the IP address of the visitor server computer is used. In embodiments where the visitor may be sharing the computing device with other users, the characteristics may include at least one characteristic that is uniquely associated with the visitor. The website server computer can use a visitor identifier thus generated to start tracking the pages that the visitor requests during the session and can generate and customize pages for the visitor by using characteristics originated from the visitor.