Oracles can choose from 3 different models, which allows them to create feeds which are public and permissioned. Feed models are at a feed level, not oracle level, so a single contract can have many feeds, some public, some subscription and some pass;
The first model is the donation based support model, where users can just send Oracles some ETH as a thankyou for running the feeds, and can choose which feeds they want to support specifically. This allows for feeds to be public and lets oracles have analytics for which feeds are being supported at a feed level
Oracles can also require a subscription to specific feed, which allows them to generate revenue from users accessing the feeds, each feed can be priced differently and some may be subscription based while others are free. Subscriptions are time based not request based.
Oracles can also create a universal Subscription pass which allows them to have 1 set fee for an address to have unlimited access to all feeds the oracle provides, this will be probably the most used model as you can have knowable revenue and expand offerings easily to generate more subscribers, offering a few public feeds for user growth and acquisition.
We are hoping to be able to turn current permissioned request based models into permissionless diy models, to cater to any use case users could want.