In an attempt to give advertisers more information about the effectiveness of ads, Facebook has partnered with Datalogix, a company that "can track whether people who see ads on the social networking site end up buying those products in stores," as The Financial Times's Emily Steel and April Dembosky explain. Advertisers have complained that Facebook doesn't give them any way to see if ads lead to buying. This new partnership is their response, as it connects real-life buying with ads seen on the site. Specifically, the service links up the 70 million households worth of purchasing information that Datalogix has with these buyers' Facebook profiles. Using that, they can compare the ads you see with the stuff you buy and tell advertisers whether their ads are working.
Source: The Atlantic. Read full article. (link)