The Real Issue with Facebook
Facebook does not sell your data. Facebook buys your data, this is their business model and its fine, they just need to be open about it.
When you log in to Facebook, they should tell you this:
"Welcome back John, while you were away we noticed that you visited these sites about buying a house: ____.com, ______.com and ____.net so we think it is likely you are trying to buy a new house. We also noticed you visited several sites about drug addiction, please let us know if we can use information to provide your better advertisements."
Facebook should provide you the ability to limit and correct the information they collect about you. They should show you what they have collected about you and what metrics they provide to advertisers to reach you.