The majority of internet users still use Google and these days it’s just a page full of sponsored links and products that are (purposely) hard to discern from the actual results. The content in the carousels for the sponsored products is richer than the content in the actual results.
Given that, I don’t think people would change their ChatGPT usage habits much if ads were introduced.
Given that, I don’t think people would change their ChatGPT usage habits much if ads were introduced.