What is Referrer Spam?

When a user follows a link from WebSiteA to WebSiteB, it generates a logfile entry in the web server logs of WebSiteB.

Most webmaster use a web site statistics reporting tool such as AWStats or Webalizer. Some webmasters (either purposefully or unintentionally) make the reports generated by these tools publically available.

One of the reports generated by most web site statistics reporting tools is a "top referrers" report. This reports lists the remote web pages that have sent the most visitors to the web site.

How are referrers used to spam?

In most web site statistics reporting tools, each top referrer is listed with a link.

That link becomes a backlink to the top referring page.

Some unscrupulous webmasters create phony requests of other web pages, just to get a spot in the top referrers list.

This technique is utilized to artifically boost Page Rank.

Unfortunately, this technique has several negative consequences:

• It uses resources (bandwitch, disk space, CPU cycles, etc...) of the "victim" web site.
• It fills the logfiles of the victim website with trash, making them useles for statitical analysis.
• It "steals" backlinks from the actual top referrers.

Preventing referrer spam

The easiest method to avoid becoming a target of referrer spam is to not publish your web site statistics publically.

If you wish to publish your web site statistics publically, you can manually ban web sites which use you for referrer spam.

If you have already been a victim of referrer spam, there are tools available to clean the spam entries from your web server log files. One such tool is Referrer Spam Fucker 3000.