That parently isn't the same as selling advertisers information. Nor is it the same as tracking and selling that to advertisers. It's entirely disingenuous to suggest so.
You are not being "sold". That entire line of thinking is intellectually lazy and meant to provoke an emotional response. I wish people would stop it.
A reasonable analogy would be conferences, are you paying for the venue, or the access to other people/speakers? does that mean the people/speakers are the product?