Facebook now controls a thin majority of online sharing, according to data released today by AddThis. The social giant makes up 52.1 percent of all sharing on the web for the year 2011 to date, up from 44 percent last year and 33 percent the year before.
AddThis released the data along with a bevy of other sharing stats. The statistics were gathered through the ClearSpring-owned company's sharing plugin, which is used by more than 11 million sites.
One insight involves Tumblr: Sharing on the service grew by 1,300 percent this year and continues to accelerate. However, AddThis did not disclose the baseline for that growth. Still, Tumblr's growth rate is faster than that enjoyed by Twitter, where sharing activity grew 577 percent and now makes up 13.5 percent of all sharing on the Internet.
Of course, when one service adds share (pun intended), another loses it. Digg and MySpace sharing both declined precipitously.
More factoids in the graphic below: