It's already aged poorly - in the first days of ChatGPT, someone already demonstrated it can perfectly mimic a YouTuber shilling a VPN every other sentence.

But in general, to the extent "chat conversation" mimics spoken conversation between individuals, then this is the medium advertisers have the most experience with - quite literally thousands of years of experience.

When I read it I thought "wow that's such an easy business model!"

This is identical to existing audio and TV ads where the personalities do the plugs. It's next generation interstitial targeted ads

It's an extremely solved problem

Also note that the cultural change around advertising within an AI chat interface could then lead to similar monetisation within human conversations too, ie WhatsApp -> WhatsAd

Alexa spams me with ads all the time - doesn’t seem that hard.