"Much like SEO, where people tried (and still try) to manipulate the rankings, some people are trying to manipulate social media. Instead of putting in the time and effort to think about their customers and create a social media profile that will naturally attract and engage customers, they are looking for a quick and easy way to build a social media presence. These fast and furious social media marketing tactics usually amount to nothing.
There’s no doubt that social media signals (i.e. activity on social media) has some bearing on search rankings, but there is still a lot of debate about the specifics. It does appear that a business’ activity on Google+ may soon become a factor in search rankings".
Via Antonino Militello