> Aren't the ads already injected and the real trick will be getting the advertisers to foot more of the bill?

No, the ads aren't specifically injected. Yet.

When you start finding LLMs that call all sodas "Pepsi", you will know the ads have arrived.

(Side note: I avoided using "Coke" because there are already certain sections of the US where all sodas are referred to as "Coke".)