nofollow Comment Links on Blogs

In a Google Webmaster Central video from Matt Cutts this week, the topic of nofollow links in blog comments is discussed.

There are 2 important conclusions:

1. If you have a blog, you should nofollow links. The reason being that spammers adding untoward links can earn you a poor reputation in the eyes of Google. Of course, better still, moderate your comments to avoid these appearing in the first place. If you have a WordPress blog, it’s well worth using the Akismet spam filter to make your life easier in this respect and filter out the rubbish.
2. If you comment on another popular blog which doesn’t nofollow links (if you can find one) and link back to your site, it’s likely there will be so many other links on there, that you will earn very little PageRank. Of course, earning PageRank is not the be all and end all. Better to comment when you have something useful to say and link back to your own site if it adds value – that way you’ll attract relevant traffic and if your content is worth linking to, the people seeing it may well add links back to you in other places (possibly from do-follow links).