For bitcoin it's easy to argue that it's useful for almost zero-cost transactions, world wide, with relatively short confirmation times. Other applications are

For bitcoin it's easy to argue that it's useful for almost zero-cost transactions, world wide, with relatively short confirmation times. Other applications are being invented: cryptographic proof-of-existence (on top of the block chain) or perhaps also distributed/anonymous DNS. You really need to see it as a powerful idea, not just a speculative asset