Hi, I was wondering if there is an app that enables loyalty cards sharing. When you open it, you can enter your card code of the Store. Now you can use a card of any other participant who entered his own card for the Store (the backend will send a random one) and your code can be used by anyone else using the service. Usually the cards are just permanent ID (shown as a bar code), so it shouldn't be that hard to implement.

While using this, the shop would have no chance of creating a profile on you and tracking you (as the purchases would be “random”), they have these data anyway. You would only give up the data you fill in when you ask for the card.

Do you know something like this? Or am I missing something important, or do you see some major flaws in this design (I don't use loyalty cards, but sometimes they could be quite useful)? Thanks