The no-follow attribute stops the search engines from indexing the destination of those links or from passing any page rank from the blog to the site it links to.

However some bloggers choose to change those links to do-follow links where links from such blogs will help the sites linked to when it comes to search engine rankings.

So who is right, and what should you do?

Well firstly let's look at the rationale behind these two differing trains of thought so we can tease apart whether these policies help or hinder your blog.

Quite early on blog commenting became a top spam method. Software was created that would allow you to submit thousands of junk comments (often simply saying things like "Great post!" followed by a link to your site) and spammers used these to generate vast numbers of links to junk sites. For a short while it worked and these spammers prospered but soon enough bloggers realised they were being taken for a ride and blog readers got sick of spam sites.

So to try and protect themselves from comment spammers, many chose to add the no-follow tag. This meant that even if a spammer *did* add a junk comment and link to their website, they wouldn't gain anything as Google would ignore that link. While this does cut down on spam to a certain degree there are plenty of amateurs who don't understand these concepts and so still continue to add junk comments.

The flipside of the problem is that some legitimate commenters started to post less. They were part of the community and took the time to add their own, high quality comments for two reasons. Sure, they wanted to contribute to the community, but they were also able to get something back (page rank) for their efforts.

When the page rank stopped flowing, many people stopped commenting and as a result a variety of blogs started to stagnate with only the blog owner adding content to the site.

And so it was that a small band of bloggers decided to bring back the do-follow comments to encourage back the legitimate commenters and instead use antispam plugins to fight against junk comments.

And on the whole this new system *does* work - though of course you are making a compromise. By using do-follow links you are building community around your site but losing pagerank as a result. It's something of a gamble.

So what should you do at your site? Well my own suggestion would be to use do-follow links if your site is a blog focusing on blogging or making money online. These folks know about such things and your efforts will be duly rewarded with interesting comments.

However outside of these niches, I would continue to use no-follow links to keep away the spammers. Also, most non-internet marketing individuals don't know the difference between the two types of links so therefore shouldn't reduce their posting of comments at your blog. This means you get the best of all worlds - good pagerank (with no leak), plenty of comments, minimal spam and happy readers.