Because there are various optimization technique which makes perfect search engine optimization. Social bookmarking sites are a place where Internet users share their Web pages, articles, blog posts, images, and videos. Pinterest is one of the Popular social bookmarking site ever. There are billions of people who are visiting Pinterest every month. So how do you find which social bookmarking sites is worth to bookmark? How to do Social Bookmarking? Here i am sharing free social bookmarking sites list with high pr which i am using on regular basis for bookmarking my site.