Via Mashable
How do you know which social sites are most popular? Aside from looking at the raw traffic numbers, a good indicator is data about which sites are seeing the most content shared on them.
Among the companies with access to tons of this type of data is AddToAny, makers of one the most popular widgets that lets content sites provide their readers with an easy way to share stories across multiple social media sites.
According to AddToAny, Facebook now dominates sharing, with 24 percent of shares from the widget consisting of users posting items to the social network. That handily beats out email (11.1 percent) and Twitter (Twitter) (10.8 percent), making the world’s most popular social network also the most popular service for sharing content. This is undoubtedly welcome news at Facebook (Facebook), as the site continues to emphasize sharing and readies its own real-time search engine.
Here's the full breakdown
