There are many schools of thought when it comes to blog commenting.
Many blogs have now taken the no-follow route, and any PR or link juice that could have been attained before has now been lost, thanks to spam comments and abuse of a pretty well rounded system. Of course, there are still ways that blog commenting can help your website, and indirectly, people have been doing this for a long time.
When you think like a marketer, you usually miss the bigger picture. When you start to think like the people that make you a good living – i.e. the visitors you get to your blog, then you start to develop a very good system – which is nothing like spam, and only helps your cause.
As blog commenting dies a death over the next hundred years or so, there will still be methods like the ones in this article that you can safely use to get some link juice and traffic. Use sparingly, and you will reap the rewards.
The first way you can use blog commenting, is to link to your social bookmarks and to your social news links. Instead of linking directly to your site, make a comment that links to a Digg article or a Reddit article. You will see much more traffic to them, and you will also get more comments approved.
Rather than link to your site, link to your Youtube videos. When people see links to videos, they are more than willing to have a look. Videos constitute a lot more web presence these days than ever before, and will get you the traffic you crave – even from blog comments.
Another great method to use with blog commenting, is to use StumbleUpon. Submitting your site to Stumble can always get you traffic, but when you link from blogs to a Stumble page, you will see a lot of traffic for very little effort.