This sounds like something for the humor section, but it really isn't. If this idea spreads, it will spawn a market in numerous private cryptocurrencies. Think of them as tradable coupons. If you don't want to redeem your loyalty "points" at the store that issued them, you can sell them for cash or trade them for "points" to use at another store that issues them. An added bonus is that the introduction of cryptocurrencies in a retailer's "rewards" program will begin making the general public familiar with the use of cryptocurrencies, which most people shy away from today.