Bitpay, peercoin exchanges and all that jazz

I read that, yet another, payment provider is integrating Bitcoin. Merchants need not to worry, the bitcoins are instantly converted. I guess this is the tap, bitcoins come out on the market and there has to be buyers. But there is a need for sinks as well, people willing to buy those. So I was thinking that perhaps it would be possible to create an exchange where you basically do the same thing, but in reverse. I.e. buying coins just before the purchase. Are you confused? Please let me clarify:

  1. Use want to buy a book.
  2. User has no coins, but has USD in an account on an exchange.
  3. User starts the purchase of the book by pointing the cell phone to jeans, qr-code, nfc, what ever.
  4. The user has an account at an exchange and coins are bought now and a voucher created.
  5. The exchange sends the voucher to the BitPay like company.
  6. The BitPay like company puts the coins in the merchant account or puts USD in their account.
  7. User has paid for the book and can leave the store.

The reason the user wants to do this, is that the fee is lower then using old plastic cards. Well… its not the plastic cards in themselves. Plastic cards could be used to trigger the whole procedure also.

And the “exchange” could of course be the same entity as the “BitPay like” company. And instead of bitcoins, peercoins.

To late(?), someone already did something pretty similar: