Web servers track use
Every time someone grabs a file using your Web server, the server logs the host name,
the date and time, and the URL requested. Ask your systems administrator about the availability of log
files for your site and the possibility of automated reports.
Log analysis tools
Log analysis tools, such as Analog (http://www2.aeiou.com/analog/), will
massage your site's log files into more meaningful statistical reports.
Example of Lamont's user log:
Take a look at Yahoo's "World Wide Web -- Servers -- Log Analysis" section: