I think you have a reading comprehension problem gk. Perhaps I misunderstood your comment... use CC for what?
Mmm. You could use swipe data and such to create payment systems. The problem would be twofold: ensuring it works correctly and safely in laggy conditions with no doubling or shorting happening, and it really would limit players to only having 'store credit' that could not be used anywhere else. At least with a manufactured currency, other stores could choose to adopt it if it becomes popular; not so with a CC controlled swipe system.
That's nice and all for me at my one store... but this would be hideously broken for sharing. Unscrupulous 'stores' could run up fake transactions in the customer's name by editing the code in their register, then go on a shopping spree. Do I reimburse the customer? How can I tell it was even fraud, and not the customer making a purchase? This would require encryption, code signing, authenticated transactions... dude, there are companies that make billions of dollars and can't get this right. I'll stick to physical coins (for loose definitions of 'physical'). All the work that prevents duping or stealing items in Minecraft gains me a measure of security for free with coins.
