Blog spam
Blog spam is a form of spamming known as spamdexing that most often targets weblogs, but also wikis, guestbooks, and online discussion boards. Any web application that displays hyperlinks submitted by visitors or the referring URLs of web visitors may be a target.
For example, in 2003, spammers took advantage of the open nature of comments in the blogging software Movable Type by repeatedly placing comments to various blog posts that provided nothing more than a link to the spammer's commercial web site. Jay Allen created a free plugin, called MT-BlackList[1], for the Movable Type weblog tool that attempts to alleviate this problem.
What is the point of this "link spam"? In theory, adding links that point to the spammer's web site would increase the page rankings for the site in the search engine Google. An increased page rank means the spammer's commercial site would be listed ahead of other sites for certain Google searches, increasing the number of potential visitors and paying customers.[2]
This form of link spamming originally appeared in internet guestbooks, where spammers would repeatedly fill a guestbook with nothing but links to their own site to increase search engine rankings.
Now after afflicting weblogs too, link spam is spreading to wikis around the World Wide Web including this one (see BambooWeb:Spam). Link spam typically appears on a wiki's sandbox page. This page[3] lists URLs and IP addresses of offending wiki spammers.
Possible solutions
- Instead of displaying a direct hyperlink submitted by a visitor, a web application could display a link to a script on its own website that redirects to the correct URL. This would prevent Google from factoring the link in its PageRank algorithm for that site. An added benefit is that your redirection script can count how many people visit external URLs, but one drawback is the increased load on your website.
