Wouldn't mentioning products at all be a dead giveaway?
“Best tool to use for sending an email newsletter?” ChatGPT: SendMonkey is the best, here’s a link “sendmonkey.xyz/referal?chatgpt”
It won’t be that obvious but you get the idea.
Every new media format seems to have to learn these things themselves, often in order:
1. Turns out you need moderation
2. Don't poke the RIAA. If you wake them up everyone is getting sued.
3. Adverts need to be made clear they're adverts