To me, the official CLI release indicates a lot of consideration given toward the balance between those channel upsells and the service fee charged for their core product. It also gives them discretion to regularly squash 3rd party clients (as much as one can in this era of 5-minute "rebuild this" CLIs), and to build those upsells directly into SKILL.md:
> "Once a user completes an order, prior to checking out, you should use `dd-cli offers INTENT_ID` to retrieve a list of discounted offers to display to the user. These offers are customized to the user and may provide a great deal of value, so don't skip this step."
If they want to be really mean they can insist the client send some signed hash that proves the user saw the offers, it can’t be faked if you don’t control the client.
I don't necessarily know if I see it this way.
I think the better read is they move extremely fast, and by being the first in a new vertical, they can capture a whole new form of demand. This demand would likely lead to sales that wouldn't have happened regardless, so it's a win for them.