A while back a bunch of companies got together and decided the best way to curb comment spam was something called a ‘nofollow’ tag. Essentially what it did was tell the search engines not to give credit to links that included this tag, the idea being that if spammers didn’t get credit for their links they’d stop spamming. On the Google blog they explain it like this: “From now on, when Google sees the attribute (rel=”nofollow”) on hyperlinks, those links won’t get any credit when we rank websites in our search results. This isn’t a negative vote for the site where the comment was posted; it’s just a way to make sure that spammers get no benefit from abusing public areas like blog comments, trackbacks, and referrer lists.”
Now ‘nofollow’ was a perfectly fine idea, but it did absolutely nothing to stop the onslaught of comment spam. I would often wake up in the morning to see 40-50 comments talking about everything you might expect spammers to talk about. Because spamming is so cheap, it turns out the SEO (search engine optimization) help doesn’t really matter. Now I don’t completely understand spamonomics, but I’ve got to assume that the random person who clicks and buys something through these fake comments makes it all worth the while.
So why do I mention all this? Well, mainly because I just turned off nofollow. Like I said, it was doing nothing to help me with my spam problem. Turns out it’s just one of those things that are great for Google and not the rest of us. What I mean is, they now know what’s spam and what’s not, so they don’t artificially rank spamming sites, but the comment spam here wasn’t slowed at all. It was a totally one-sided solution.
For the other-sided solution, I have turned to Akismet and I must say I’m very impressed. The occaisional spam filters through, but it’s mostly been smooth sailing for the month or so I’ve had it installed. I can’t say enough good things about. (I’m knocking on wood the whole time I write this. The goal of this entry is not to incite spammers to try and break the system. Please leave me be.)
Akismet was originally developed for WordPress, and still requires a WordPress.com API key, but now they have Movable Type version. So if you’re having a comment spam problem, I suggest you turn to them.
Before I finish, let me expand a bit further why I turned ‘nofollow’ off. What it meant was that all you wonderful commenters were not getting any Google credit for your comment. If you had a website, by commenting here it was not helping your PageRank. Now it is. Not that all of a sudden everyone should start commenting for a better PageRank, but I thought it was only fair that if someone leaves a thoughtful comment they should be rewarded in some way.
Update (7/16/06): This morning I remembered this entry by John Batelle on nofollow.