The prepaid and pay-per-use models are already very close to the ecash sat stamp model, as both charge per use.

The prepaid model is an account-based model, where after recharging Lightning Network sats, only the corresponding account can spend the balance.

The ecash sat stamp is a cash model, without accounts. Users send Lightning Network sats to an ecash mint and receive ecash sat tokens. These tokens can be shared with others for use.

Both models involve third-party custody of LN sats.

The stamp model offers greater flexibility and privacy.

Under the prepaid model, the relay has to take on more tasks as it needs to keep accounts for various users.

In the stamp model, the client takes on more responsibilities, as it needs to attach the ecash sat token to the note.

We believe that more and more nostr clients will incorporate built-in ecash wallets. nostr:note1mqwnfu7rrmvqd00jyhkkrlrxqhtyk4c5k2pfvulun8hyupx9t7nsqwma05