Not So Anonymous: A Computational Approach to PRivacy (seas.harvard.edu)

Quoting Sweeney in the article, “One experiment after another has shown that people will make poor decisions about anything that involves their privacy. They want the new utility, they want the new shiny thing, because we tend to discount that any harm is going to happen to us, even when we’re told that it could.”

I'm very much a privacy advocate, but if the user is willing to trade their privacy for some added-value, then so be it.