But you probably don't represent the average Facebook user. Most of my non-tech friends share everything - FB knows pretty much everything about them, and certainly for some of the younger ones, FB has become their primary communication platform.
For most of them, paying with Facebook would just be easier than using something else / remembering more details etc etc. And they probably trust FB more than they trust other companies with far less visibility (although most them have used their CC without any thought or concern on a load of different websites).
FWIW and personally, I completely echo your thoughts - although I'm sure I'd end up giving my CC details to FB as soon as a website that I needed to buy from offered no other method to pay than the FB one.
For most of them, paying with Facebook would just be easier than using something else / remembering more details etc etc. And they probably trust FB more than they trust other companies with far less visibility (although most them have used their CC without any thought or concern on a load of different websites).
FWIW and personally, I completely echo your thoughts - although I'm sure I'd end up giving my CC details to FB as soon as a website that I needed to buy from offered no other method to pay than the FB one.