I don't think that's it. FB doesn't 'sell' data, rather, they allow advertisers to 'target' people. The targetting dimensions are right there for everyone to se

I don't think that's it. FB doesn't 'sell' data, rather, they allow advertisers to 'target' people. The targetting dimensions are right there for everyone to see, I'm doubtful that you're going to find the ability to target people on 'recently purchase meds'. I think this is a case of companies asking users to provide information on in-app sign ups.