The truth is it’s difficult, if not impossible, for web publishers to know precisely how many people visit their sites. Web servers track IP addresses, not people. So if I have a PC at work and one at home and I read Wired News at each place, Wired’s server counts this as two visits — without being able to tell that it’s just one person behind those two visits. Likewise, 100 people a month might use a PC at a library, university computer lab or cybercafe to visit Wired News, but our server would count only one IP address.