User data (and the resultant behavioral prediction) is the new gold rush. Even if the data is not immediately useful, it can be stored and used later.

There's the (now) old saying, "if the product is free, then you are the product" but that's not entirely accurate. You are the source of raw materials. These materials can then be fed into a model which will predict your behavior. Right now this can be seen simply in the space of funneling content to you, in order to get you to buy things. But companies are not governments and can sell their product to anybody (including governments) in order to predict or direct your behavior.