Sites that have a high number of social shares, comments, tweets and +1s tend to rank better in Google, according to a new report from Searchmetrics.

And of all the four main social networks it appears that Google+ actually has the strongest correlation with high search rankings.

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.

Websites that rank in the top positions for Google usually have a large number of social signals, but then it could just be that people naturally share popular, well-ranked sites.

The correlation also holds firm at the other end of the scale, as sites with low rankings also have a lower number of social signals.

The data shows that +1s from Google+ tend to have the strongest correlation with high rankings, followed by various types of Facebook shares.

Pinterest has the lowest correlation of the four main social networks.

Google+

The emergence of Google+ in the report is of particular interest. When Searchmetrics produced the report last year it was not possible to make any meaningful statements about G+ due to insufficient data, but in 2013 G+ signals are just behind tweets in absolute terms.

But more significantly, +1s show the highest correlation with good rankings.

There are obviously caveats to this though, not least that it’s still far more common for people to share things on Facebook than on G+. Therefore it stands to reason that sites lower down the rankings will have more Facebook shares than +1s.

Furthermore, the new Econsultancy/Netbooster UK Search Engine Marketing Report 2013 shows that 51% of agencies say Google+ has had no impact on their search campaigns, so clearly the jury is still out on whether there is actually any causation between high rankings and a high number of +1s.

Even so, is it time for businesses to begin taking Google+ more seriously? We’ve previously looked at how top brands use Google+, and overall there seems to be little interest in maintaining an active brand page.

Among the most indifferent brands are Walmart, Best Buy and LL Bean, which have established brand pages but done nothing with them.