There are a number of links between social media sites and data collectors. Nexopia, on the commercial half of their site, had relationships with marketers in which they claimed to have information on how teens thought and purchased, because of their data set. I'm quite sure that Facebook is using that. That's what they use to drive their IPO: we know what people want. That's fine within the limits of everybody knowing that they have that information and are using it consistent with what they said they could use it with.
On October 18th, 2012. See this statement in context.