Recently one of my sites was suddenly flooded with referrer spam (just as annoying as any other spam variety). What exactly is referrer spam? From Wikipedia :
Referer spam is a kind of spamdexing (spamming aimed at search engines). The technique involves making repeated web site requests using a fake referer url pointing to a spam-advertised site. Sites that publicize their access logs, including referer statistics, will then also link to the spammer's site.
The most effective way to deal with this seems to be the creation of a few ReWriteRules for your webserver - commonly done via an .htaccess file for Apache. A couple of articles I came across whilst working out how to best deal with this :
Block Referrer Spam on I Love Jack DanielsThis is a great look at various ways (read the comments) to deal with this problem, mostly using .htaccess files.
Referer Spam Redux (Kuro5hin)A summary of the problem and useful links to other articles. Once again, the comments are illuminating.
If you're looking for ways to deal with
spam on Dean Allen's (Textism) Refer, later versions offer the following section in refer.php :
* Fill these in to halt the recording of unwanted referrals
(e.g., an overly frequent google search, or a robot that
inserts a referrer for every page it visits) by matching a
distinct phrase. To add more, just duplicate a line and put
a different match phrase inside 'quotes'. */
$rcfg['exclude'][] = 'blo.gs';
$rcfg['exclude'][] = 'weblogs.com';
$rcfg['exclude'][] = 'technorati.com';
$rcfg['exclude'][] = 'paris-hilton-video.blogspot.com';
Simply copy/paste the last line, insert any text from your spam; rebuild.