A blockchain-based proof-of-identity loyalty points system. Though the challenge will be to have it integrated to brick and mortar stores that are more often than not laggers in tech adoption.

The idea is certainly interesting.

Edit: @buzz.lightyear also brought out 2 interesting points. There is no mention of which blockchain will they bootstrap the protocol on, as well as the logic behind adopting a blockchain database when a typical centralized database would make work far easier with none of the challenges of a blockchain.