Burger King has launched its own crypto-currency, called WhopperCoin.
They are offered in reward for purchases. 1700 WhopperCoins can be redeemed for a Whopper burger.
The BlockChain is being managed by Waves: http://wavescommunity.com/blt-with-dlt-have-it-your-way-with-whoppercoin-on-waves/
(n.b. the Waves web site doesn’t use HTTPS, rather odd considering their area of expertise)