> Back in 2011, folks may remember the controversy that erupted when Moz found a similar correlation between higher rankings and Facebook activity. At the time, Google claimed they didn't use Facebook shares for ranking websites. Dr. Peters concluded that the relationship between Facebook activity and higher rankings was likely not directly related, but probably caused by overlapping factors such as links and high-quality content.
> Now in 2013, there's strong reason to suspect it's different with Google+, and that the relationship between +1s and higher rankings goes beyond correlation into the territory of actual causation.
While Facebook / twitter are lagging signals from google's access perspective, G+ is contemporaneous: "Posts are crawled and indexed almost immediately"