Build quality links on forums, blogs, and social networks
While SEO professionals are still unsure whether SEO is directly impacted by social signals (like the number of Facebook likes or Tweets your page has), one thing about Social Media and SEO is no longer a question. Social Media is a valid and efficient source of links.
According to Google’s Matt Cutts, Facebook, Twitter, and Google+ pages are indexed and displayed just like any other pages on the Internet — and can therefore be considered valid links.
All of this makes Social Media Marketing an integral part of SEO — Read More Here: