You ask Chat to add some tags to its output, via your prompt. You get your browser to filter output that is not tagged properly.
Counter measures will need another LLM "AI" to filter out efforts to filter out ads from my prompts. However, when openai's adversary is their customer, my money is on me!
That's a dumb way to do advertising. The "right" way is to shift all the weights a little, so that it's influencing you with everything it says but you don't even see it happening.