1. A method to monitor user events relating to a web page provided by a first server to clients requesting the web page via the Internet, the method comprising: embedding a computer executable monitoring instruction in an HTML file which, when executed by a first client or a second client different from the first client accessing the HTML file, generates monitoring information concerning user events relating to the web page associated with the HTML file; embedding a computer executable transfer instruction in the HTML file which, when executed by the first or second client, transfers the monitoring information to a data collection server; responding to a request for the HTML file from the first client by downloading a copy of the requested HTML file via the Internet to the first client; responding to a request for the HTML file from the second client by downloading a copy of the requested HTML file via the Internet to the second client; and receiving a report from the data collection server that did not transfer the copy of the HTML file to either the first client or the second client, the report concerning the user events of the first and second clients with respect to the copies of the HTML file.