Posted Jan 21, 2005 in Spam.
There has been a great deal of discussion about
rel="nofollow". Google has acknowledged that comment spam has become a real problem for weblogs, with PageRank-hungry businesses spamming blogs to try and increase traffic to their sites. Google's solution is to suggest that bloggers attach the
rel attribute, with a value of
"nofollow", to links that should not be indexed by Google. Since Google won't follow these links, no PageRank advantage can be gleaned from them.
I applaud Google's efforts to try and curb comment spam. I have suffered from it myself, although perhaps not as much as people who use mainstream blogging systems. However, I cannot imagine this approach will be particularly successful.
Spam is a numbers game. Email, referral spam, and comment spam are cheap ways to reach a target market with a business message. Even if no actual message is given, some people will follow links back to a website that carries the message. And even if it doesn't happen, PageRank will rank the message higher and higher, increasingly the likelihood of a message being read.
rel="nofollow" solution will probably make some impact, but the result will be that spammers will simply move to a new feeding ground. The real tragedy of the tactic will be that
rel="nofollow" will be applied to quality links as well. Unless a blogger is prepared to moderate each and every comment, or build some kind of recognition system into each comment,
rel="nofollow" will simply be applied to all comment links, even if they are not comment spam. PageRank will no longer follow these higher-quality links, and the system will become less effective at ranking.
Maybe it is the lesser of two evils. At least something is being attempted. I still believe that some kind of human test is the only way to win this particular war, which usually involves making the commenter answer a simple question that a computer cannot answer. If combined with user registration, I expect it would kill comment spam completely.