1. A method for tracking activity on a web site comprising: storing a web site on a first server coupled to a network; using a second server to place a third-party cookie on a visitor computer to track activity of the visitor computer on the first server; loading a web page from the web site on the visitor computer; executing computer code associated with the web page at the visitor computer; sending a data request to the second server responsive to execution of the computer code; sending the third-party cookie with the data request; opening the third-party cookie at the second server; reading an identification code in the third-party cookie; sending the identification code to the visitor computer with the requested data; and associating the identification code with a first-party cookie at the visitor computer.