The End of the Ad-Free Era: OpenAI Launches ChatGPT “Go” and Sponsored Responses to Fuel GPT-5.3

### Executive Summary: OpenAI has initiated a U.S. pilot to place clearly labeled, privacy-protected advertisements at the end of ChatGPT response threads while preserving an ad-free experience for premium subscribers; the company frames this as a necessary step to broaden access and expects ads to be a minority of revenue. The report also notes Anthropic's Super Bowl critique of the move and that OpenAI will release an updated chat model to help mitigate user dissatisfaction.