The only reason those 3 aren't selling data is that they have the vertical integration to launder and monetize it themselves. They don't have to sell it, becau

The only reason those 3 aren't selling data is that they have the vertical integration to launder and monetize it themselves. They don't have to sell it, because they can keep it, productize it, and then sell the targeting information to advertisers, without revealing the underlying data. -- Imagine a Google, Facebook, or Microsoft without an ad network and devices/apps to serve it on. Then tell me they wouldn't immediately be selling their tracking data to anyone who would buy.