A recent study conducted by Sharethis (a social sharing button provider) showed that Facebook leads ahead of Twitter and other social media services in content sharing.

Source: Sharethis It is interesting to note that Facebook is ahead of Twitter and email combined. The graph above shows the data for the shared links that are clicked which is less than the links that are shared but not clicked. Facebook being the top website in the world has most engaged visitors and the sharing rate increased by 45% year over year.