Every one of those "likes"—a billion statements of preference every day, 365 billion every year, at least—will get filed back at Facebook HQ. It is difficult to overestimate the value, to Facebook, of all this activity. Remember that the social network already has the world's largest database of connections among people. Now, very soon, it will also have the largest database connecting people to the things they enjoy, whether those things are news stories, restaurants, songs, books, movies, jeans, cosmetics, or anything else. Yes, lots of other firms mine our online activity, but Facebook's system will be all the more powerful because it is voluntary. We, Facebook's hordes, are actively filling in the slots in its database, giving the company an extremely accurate picture of ourselves and our friends. No other company will have anything like Facebook's towering database of human intentions and desires—not even Google.