Today I was checking backlinks of my site and i found that most of backlinks coming from blogs. I never post any content on these blogs. I m worried, why they place my link and how do they get links. I want to know 2 things: 1. Are these links helpful for SEO? 2. From where these blogs are getting data? Here are some sample blogs. http://www.automotiveheritagemuseum.com/ http://www.pamhawk.com/ http://www.cupeesh.com/ Thanks in advance.