Social commerce services like Blippy, Swipely or iTunes Ping make users' purchases public, which is obviously cool, because you can build nice review or recommandation services on top of that.
Big players like Amazon and Visa are said to be thinking about it, too.
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?)
http://activitystrea.ms/schema/1.0/purchase
First suggested here: http://groups.google.com/group/activity-streams/browse_thread/thread/943a65a3889a6310
None.
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