I just realized how easy it would be to seriously skew Netcraft's
webserver results (http://www.netcraft.com).  If you have your own DNS
server, you could add a wildcard entry to point to your main site.  Then
whenever someone types in foo.yourdomain.tld or bar.yourdomain.tld, it
resolves to your main site.  For example, in your zone file you'd have an
entry like this:

*      IN      CNAME   yourdomain.tld.

So next, you could go to the Netcraft site and add in your domain to be
monitored.  You could add in 1.yourdomain.tld and 2.yourdomain.tld and on
and on and on.  So, I'm not encouraging anyone to do this, but I just
wanted to point out how unreliable the Netcraft "stats" really are and how
easy it would be for someone to skew the results (if it's not happening
already).
~M