Gimmick or game-changer? Behind the hype of Bitcoin and blockchain

Whether you see the world of cryptocurrencies as a volatile speculator’s market or the new model for a decentralised economy, brands from Kodak and Burger King to startups in the loyalty and betting categories are all exploring the possibilities they offer.
Cryptocurrencies and the technology that enables them to exist, blockchain, are described at one extreme as gimmicks that simply make good fodder for PR stunts, and at the other as a new economic paradigm. So which is it?
Bitcoin has be