Social media doesn't play an important role in search engine ranking, especially Likes, Tweets etc. However, you can gain positions from links, such as a top ranking listing in Google for your company name with a Facebook URL.
However, obviously Social Media plays an extremely important role for creating/maintaining traffic. Inclusion is necessary for success.
Social media marketing is becoming popular among internet marketers not only because it's a great way to find leads and incredible website traffic, but also because there's a lot of talk going on in the world of SEO that Google and other search engines may factor in a site's social media activity in their algorithms. More organizations get into it because of its success. It's like they're publicizing their item without the audience even seeing it.