QUOTE(jasminjew @ Apr 18 2013, 05:17 AM)
What do you mean by blog commenting?
Blog Commenting allows you to create a backlink from the blog you commented on to your blog. Google considers each backlink as a vote for your blog from the other blogs. This is oversimplified, however, the higher the PR of the blog you commented on, the more that vote counts toward raising your Page Rank and maximizing your SEO.