As OpenAI prepares to meet the scrutiny of public markets, it has turned to one of humanity's oldest commercial arrangements — the advertisement — to sustain the free exchange of knowledge it promises its users. The rollout of ads on ChatGPT in India, one of the platform's most active markets, reflects a company navigating the tension between open access and the enormous cost of intelligence at scale. In choosing advertising over exclusivity, OpenAI is betting that monetizing attention is more sustainable than pricing out the many to serve the few.