Bloggers (turned SEOs) do blog commenting for different purposes like some do it to build backlinks, few do it to increase Alexa and few very do it to increase awareness about their blog.

Blog Commenting in SEO helps to get visitors to your blog or website and most importantly to create a bonding with your fellow bloggers.

Blog commenting is best way for interaction between bloggers and blog readers. It is an action wherein visitors or blog readers leave a comment, reply to readers’ comments, or the author himself answers or replies to visitors questions and comments.

Hi there !!!!
Blog commenting is the highly recommended SEO activity to increase traffic or you called natural traffic to the website. Blog commenting means making comment or giving your views on some other website but of same interest along with placing your links. It has very positive effect on the website hence benefits in more than one way. Thanks.........

Well a Blog Commenting is one of the best off page step. Its helps increase the website do follow links and ranking on major search engines.

Simply if you are commenting on any blog created by someone else is blog commenting, this is a off page optimization technique in seo and very useful way to creating a backlinks.