As we all know, backlinks are one of the factors that search engine algorithms use to determine the rank of a page. However, there are a number of things you should watch out for:
1) Make your comment related to the post.
I see so many crap SEO comments on this blog. They are just generic comments that could apply to any blog, and always followed by a link. These are obviously spam backlinks (which get deleted).
If you're going to try to cultivate backlinks in this way, make the comment related to the post - add your thoughts on the subject or why the post was good or bad (ps. you don't have to go brown-nosing in your comments to get a backlink, nothing stimulates conversations more than some precise criticism)
2) Does the comment count?
You may not realise it, but many websites insert the "nofollow" attribute in the anchor tag to any links posted in the comments section. This automatically stops them being counted in the tally of backlinks to a web page.
<a href="http:/www.targetsite.com/" rel="nofollow" >Link Text</a>
**Hey Backlinkers! Blogger.com & Blogspot.com uses the No Follow tag**
So all those generic comments on this blog with backlinks are just a waste of time for those "backlinkers".
Here's a neat trick to check which blogs don't have the "nofollow" tag applied. Download either firebug or SearchStatus add-ons for firefox. Both allow you to interrogate a web page and find which links have the "nofollow" attributes.
To find out more about search engine optimisation, check these posts with the SEO label.