Search engines unite to fight spam
In a rare show of unity, all three of the major search engines have acted together act to fight the practice of comment spam. This is the practice where someone will comment on a particular article and add a link to their own web site purely to gain additional rankings in a search engine.
Because search engine spiders will follow any link on a page, and award the linked site a page rank value based on the rank on the originating page, the practice of comment spam has become an epidemic throughout the web. It is a particular problem with blogs, forums and sites with guest books where the practice of commenting is encouraged.
Initially proposed by Google and now adopted by both Yahoo! and MSN as well as some of the major blogging sites such as Blogger.com TypePad, MovableType, LiveJournal, and WordPress, the search engines will now recognise a new attribute known as ‘nofollow’. This would work in the following format
My Great Website
If the ‘nofollow’ attribute is encountered the Google spider googlebot will not follow the link. Google says it will also not use the link in calculating link popularity or parse the anchor text for relevancy. Note that the ‘nofollow’ attribute will only apply to that particular link and doesn’t affect any other links to a page or its listing in the Google index.
It won’t eliminate the practice entirely as many comment spams are automatic and enough real people will click on the link anyway. Nevertheless, it is at least a first step in reducing the problem.