The ledger-only tier is what Deloosh can do from send history alone before anything is connected. It supports useful work while keeping purchases and other unseen data explicitly out of scope.
For example, the dormant-subscribers Signal can use delivered-marketing and recorded-click rows from the ledger, while a purchase-aware play stays locked because the ledger cannot show what someone bought.
See DATA-6, The ledger-only tier: what works before you connect anything.