Amazon has unleashed its own virtual coins. You can purchase them one for a penny and use them on the Kindle Fire and the ap store. The more you buy the better your exchange rate so if you buy 10000 coins it only costs $90.00. You can use that money to buy books that you want, like, say the Castles & Crusades Players Handbook . . . that was some subtle product placement right there . . . with your Amazon coins.
This virtual commerce may or may not work. Who can say, the bit coins are doing very well in their own exchanges. If successful Amazon will no doubt allow one to buy and sale in Amazon Coins.
But really, they should call these Amazing Coins! They won't ever have a better opportunity.