Nofollow and Comment Spam

Google recently announced an interesting ‘solution’ to the comment spam problem. If you add rel="nofollow" to your links Google, yahoo and MSN will no longer consider them ‘votes’ in their algorithms. To answer the Question of the Day, I don’t think this will make much of a difference to comment spam. However, as every little bit counts, I’ve implemented it here.

I feel that nofollow has one fatal flaw, spammers won’t bother to check whether or not your site implements it. They’ll just spam you and write off their bandwidth. As noted by Mark Pilgrim, and dug up by Sam Ruby spammers don’t read the comments, they just write them.

Rel nofollow will do as much to stop comment spam as filters have to stop email spam. Which is to say, it will make a dent in the economics of the spammers, but do nothing to reduce the amount of spam I receive.

Assume you’re a comment spammer, currently you instruct your zombie network to submit 2,000,000 links to a variety of wikis and blogs around the world. With nofollow in place, some of the sites you target won’t give you any ‘google juice’, some of them will.

These attacks cost the spammers almost nothing, reducing their payoff will still leave them with a pretty compelling proposition. In the time it takes you to check whether a site uses nofollow, you could simply spam it and move on. In the time it takes you to build a ‘rel no follow checker’ you could have spammed 500,000 more sites.

Decent spam filters have reduced the payoff to email spammers, I still get 70-100 spams a day. Nofollow will reduce the payoff to comment spammers, but sadly I feel I will continue to receive comment spam.