Social media is fast becoming the optimal way for websites to rank at the top of search engine results.
Social signals are the likes, shares, votes, pins, or views people place on Facebook, Twitter, LinkedIn or other social media sites that filter out to the various search engines.
Social signals indicate that your website is being talked about by consumers, and this improves your SERP ranking because search engines view social signals as trusted “recommendations”.
Increased social signals indicate good domain authority and demonstrate a URL's value. When large numbers of users share and like a website on social media sites, it indicates that the website is genuine and contains substantive or entertaining content.