Comment links of this blog are now DOFOLLOW!
But what is dofollow?!
When you make a link to another website, it’s possible to specify the nofollow attribute. It tells Google to do not follow the link; it follows it but it won’t give popularity to it. It’s a bad thing, because the major advantage to have a backlink to your website, is that it makes you more popular (at Google’s eyes); which avoids nofollow links.
More external links (dofollow links) there are in a page, more the importance given to them is divided. It’s why most of bloggers don’t give any importance to links of people that comment; to do not reduct importance given to their own links to internal pages.
BUT if a visitor makes a relevant and long comment, it should be right to give him a free backlink, not nofollow link. Lots of people write comment all the time only for that, but it may be a good motivation for people to post comments they wouldn’t have posted else. You must not forget that it’s free content for the website, it’s only an exchange of services.
You must not exagerate, for instance to use an anchor text nickname to increase directly your ranking (e.g. poker texas hold’em), but it may be tolerated, even if many blog editors take it like a lack of respect.
In my case, if someone posts a comment and it’s a relevant comment, I’ll approve it without problem!