Having an immutable database that was able to track fraud ratings, along with when exactly it occurred with the data available at the time was pretty cool. You could probably do it with other tools, but having it all in one product was nice.

The cryptographic verification was helpful for legal defence. I can't think of any other uses so we may have been their only customers.

It's just increases scope x100 to get anything done, so few do it... but if the tooling was available, almost all stateful applications would benefit from it.