Social discovery and sharing platform Shareaholic released a report looking at referral traffic data from social media sites in Q4 of 2013. Here’s the short of it: Facebook, Pinterest, StumbleUpon, and Google+ all gained, while Twitter, Reddit, YouTube, and LinkedIn lost. But the data says that Facebook, Pinterest, and Twitter combine to dominate so much of the Internet’s referral traffic that the numbers don’t actually speak for the other sites in this category – combined, the rest of the sites only had 1% of the total share, so even as their shares jumped around rapidly it’s hard to take those numbers seriously in the big picture. So, for the top three, Facebook’s referral traffic share rose from 10.37% to 15.44%, and Pinterest also rose from 3.68% to 4.79%; Twitter essentially remained level, changing from 1.17% to 1.12%. The takeaway? Facebook, as usual in these sorts of studies, is the real winner, having driven more than twice the referrals of all other platforms combined.