Linking Backlinks are one of the most important factors considered by search engine when calculating page rank. There is a black hat approach. Black hat seo practitioners use link farms to exchange numberous links with other websites. The links are often used without any logical context. Ordinarily, Search engine will check the number of websites that link back to your site to determine how your site rates for a particular keyword. The problem is that the use of link farm is considered spamming and your site will eventually be black listed. White hat seo relies on the natural exchanged of links often in the context of online discussions new pieces, article submissions and social media sites. Such links may take much larger to acquire, but the provide a more sustainable results. Please share your views about this over here.