The roughly 200-day-old ad business is now available in more than 40 countries, with self-serve access expanding Monday

Two hundred days in, OpenAI has something Google and Facebook needed years to assemble: a billion-user surface, a self-serve pipe and a billion-dollar pace.

OpenAI's move to serve ads in ChatGPT earlier this year drew ridicule from its chief rival, Anthropic, in the form of a Super Bowl commercial.