Social bookmarking is a way for people to save their favorite webpages online. By using social bookmarking online people can access their favorite bookmarks from any computer and share them with other people. Bookmarks are usually stored with tags, single words that describe a page, making it easy for people to search for similar bookmarks or find bookmarks they have saved.
If you are using dofollow sites and you want Google will add it on backlinks so always make sure the links must come form different IPs and I do not think all these sites are from different IPs.
