I agree; however, I don't think advertising is the point. As I see it, data collection and user profiling is the point. It is then this, I'm betting, that they market to anyone willing to pay them for it.
To me, this is more insidious than advertising. They are spying on their users with the intent of marketing the data, or using the data in ways that allow them to try to get to "know" users so that they can market that data to outside entities.
I am betting there is a money making basis to this, and since it is unlikely based on their behavior, that advertising is their money making shtick, data collection and profiling their users is, as I see it, the only remaining money making path for them.
After all, what is sales and marketing. Thinking like a marketer which I am not, what better way to figure out how to get you to buy one of the products I am marketing than by learning everything about you that I can in order to play on those aspects to get you to buy my product even though you may not necessarily need or want my product.
For example, cell phone ads that make the cell phone sexy - obviously aimed at males, or cell phone ads that point out how its an "X"G phone - obviously aimed at the tech geek who has to have the latest "G" string.
My point is that they are profiling their users, and that, IMO, makes it especially dangerous and insidious.