A new report by Searchmetrics shows a strong correlation between a site's social signals and its ranking in Google SERPs.
Websites that rank in the top positions for Google usually have a large number of social signals, with Google+ apparently having the biggest impact.
The report is based on analysis of 10,000 search terms from Google UK, using the first three pages of results.
It’s important to point out that this is a correlation rather than causation, so we can’t necessarily say that social signals definitely lead to higher search rankings. But it does seem to suggest that there’s some relationship between the two.