Semil writes: "After running a few tests with retailers on Facebook, GraphScience realized it could leverage the social graph information from Facebook’s API in such a way that it could deliver four to eight times ROI for retailers, a repeatable measure that helps solve one aspect of the large questions hovering around Facebook’s ability to make money today."

These retailers aren't just running ads, they're using ads to bring people to their websites, put items in shopping carts, and buying them. Cool.