Does Google use data from social sites in ranking?
This is an old video from Matt Cutts in 2010, on social media sites contribute to increasing your google rankings. It is a minor single and I mean a minor single as more traffic to your website does help with google ranks.
Google looks at reputation on social media. It worth watching.
Matt Cutts on social signals
Matt Cutts is Mr Google... what he says goes... please watch this video on social media and Google search results