There is some argument about terminology, whether the notion of blockchain includes the peer-to-peer distribution and consensus mechanism (eg proof-of-work) or not. (In my view, it shouldn't.)<p>Git uses a somewhat extended version of a blockchain (a directed acyclic graph instead of just a linked list).<p>I think it's a cool technology, and has many applications where you want an immutable sequence of records. But it's not a panacea, and the current hype is overblown.
Close to cryptocurrency, but reward points seem like a good use case. That is, something very seamless to move rewards around whether they were earned for a hotel, airline, credit card, etc. Points.com takes a pretty big cut for that (centralized) service today.<p>Money transfer as well, maybe. I don't know the space well, but it seems like MoneyGram, Western Union, and similar charge a high premium for their services in some cases.
Almost anything that needs validation/integrity.<p>Luxury handbags? Check the blockchain to confirm it is real.<p>Need goods transported at a consistent temperature? The blockchain can validate that your shipment did in fact remain (or not) at a certain temperature.<p>Want to buy a scalped ticket? Scan the QR code and confirm the ticket is usable.
Use of clearing for financial markets. You'll be able to verify that party A has the instrument and party B has the currency without needing to go through a separate company.