OpenAI plans to test ads in ChatGPT, beginning in the U.S. from January 16, to monetize its platform, which serves over 800 million weekly active users. CEO Sam Altman acknowledges the risks of ads but emphasizes user trust. Subscribers to ChatGPT Plus and other premium tiers will remain ad-free. Ads will appear clearly within response boxes, with assurances against selling user data or targeting minors, amid the rising costs of maintaining AI services.