Breaking: Clearspring acquires AddThis

Widget infrastructure provider Clearspring has acquired bookmarking and distribution tool / button AddThis.

According to Quantcast, the AddThis (destination site?) is reaching about 1.5M people per month, and according to their site, their button was served 20 billion (!) times this month via partners that include TechCrunch, Zappos, and CBS.

The AddThis acquisition gives Clearspring a much stronger position in decoupled distribution tools to complement its already strong widget wrapper / analytics package.  In the world of distributed widget infrastructure / plumbing, it's starting to look like a two horse race - Gigya and Clearspring.

For more, see ReadWriteWeb.