This is, of course, a problem relevant to many decentralized systems. A user pays me $1 to store their data for 1 month. How do they know I’ll actually do that, and not run off with the money partway through the contract?

Bonding. If there’s a technique which allows for fraud 1 year down the road, then I need to have that much collateral locked in a trust for 1 year. If I behave, I get the collateral back, else I lose it. This discourages me from participating in detectable fraud over that year term.