It can't be done in general. "Hey Gemini, give me an exercise suggestion". When it suggests going for a run, how much of that is real and how much comes from the Nike campaign? Even google will not know the answer to where ads begin and end.

Advertisers might feel a bit weird about paying for something they cannot track, but for eg pharmaceutical companies have been taking doctors out to dinner for forever. Paying to sway the opinion of a communicator instead of paying to communicate is not necessarily new.