There'a a key nugget buried in this morning's New York Times story about how Facebook is going to give its users the ability to see why certain ads are targeted to them. Starting this week, the Times reports, "the company will tap data it already collects from people’s smartphones and other websites they visit to improve its ad targeting. Users can opt out of such extended tracking, but they will have to visit a special ad industry website and adjust their smartphone settings to do so."
In other words, Facebook is giving users a glimpse of what marketers already know about them, but it is also going to allow marketers to target users based on more detailed information, even though it won't actually give the marketers the user data—which makes sense, given that Facebook's business model is largely built on the data you provide.
Facebook wants to know where you're from, how old you are, who you're friends with, what industry you work in, your likes, your relationship status, where you vacation, etc., etc., in large part because marketers want to know those things. I'm reminded of this every time I log on. I never told Facebook my hometown, but it's been guessing ever since—New York City? Philadelphia? Honolulu? Baltimore?—in a box that appears prominently on my profile page. I keep avoiding answering, mostly because I relish the fact that there's at least something Facebook doesn't know about me. There's plenty else the site has figured out. (I wrote recently about the time Facebook guessed what shoes I was wearing.)