For example you could implement a credit system where anyone could be a creditor and vote (with their digital signature) what requests get approved. Then, once the money changes hands, the smart contract would automatically deduce que periodic payments, including the interests, and distribute it to the lenders in the correct proportions. If a payment is missed, a penalization or increased interest could be implemented.

I don't know if this would be currently possible with Ethereum because I haven't looked very deep into its technology, but if not I'm pretty sure some blockchain will allow this kind of interactions.

For more examples, check: https://www.ethereum.org/token