There's a lot of interesting stuff going on with computational blockchain platforms (Ethereum, Stellar, EOS). Basically they make it possible to write and deploy code - with nobody's permission, no approvals or policies or corporation necessary - that can ensure that
when a user performs an action, they receive something of value. And they can do this without the user needing to trust that the terms of the transaction won't change later.
One of the hardest parts in many software markets is in designing incentives, making sure that the user has a reason to perform the action you want them to perform. And for startups, there's the added problem of getting users to trust that the incentives you advertise will actually hold. I might trust Stripe or Google to actually deliver the money they say they are collecting on my behalf to me because they are big established companies, but I'm certainly not going to trust a random payment processor who just started up and is advertising on a forum somewhere. But once platforms like Ethereum actually have decent UIs and reasonable transaction processing rates, you can just inspect the code of the smart contract that collects Ether (or Dai is the new payment hotness, now) from users and disburses it to the parties that were involved in producing whatever service they use.
The permissionless aspect of this whole system is very similar to the early WWW, where you could just stand up a website to do something useful and if it was good users would flock to it. That's why I'm excited. The cryptocurrency world gets a lot of bad press because a lot of the early users were quite gullible and a lot of the early use cases were in finding better ways to scam them, but there's real, fundamental technological innovation behind it.