OpenAI has started serving advertisements inside ChatGPT for logged-in adult users on the Free and Go subscription tiers in India, working with WPP and Omnicom as launch agency partners and lining up more than fifty brands for the initial rollout. Paid Plus, Pro, Business, Enterprise, and Education subscribers will not see ads. A self-serve ChatGPT Ads Manager, letting businesses of any size run campaigns with daily budgets as low as a few hundred rupees, is scheduled to open on September 4. India is OpenAI's largest market by weekly active users outside a small number of countries, with more than 100 million weekly users and usage that has roughly doubled year over year, which makes it a logical testbed for ad-supported monetization before any wider rollout. For people building products on top of large language models, this is a notable signal: it shows one of the best-funded AI labs concluding that subscription revenue alone does not cover the cost of serving hundreds of millions of free users, and that advertising is viewed as a viable lever even for a conversational interface rather than a traditional content feed. Teams designing their own AI-assisted products should watch how OpenAI balances ad placement against trust and response quality, since getting that wrong in a chat interface is riskier than in search or social feeds. The eventual self-serve ad API is also worth tracking for teams building on top of OpenAI's platform, as it could open a new distribution and monetization channel.