engine - 5:24 pm on Jun 1, 2012 (gmt 0)

Facebook Users' 'Like' Becomes An Ad, or 'Sponsored Story' [nytimes.com]

Within days, friends of Mr. Bergus started seeing his post among the ads on Facebook pages, with his name and smiling mug shot. Facebook — or rather, one of its algorithms — had seen his post as an endorsement and transformed it into an advertisement, paid for by Amazon. In Facebook parlance, it was a sponsored story, a potentially lucrative tool that turns a Facebook user’s affinity for something into an ad delivered to his friends.