OpenAI says its advertising business has reached a $1bn annualised revenue run rate as the company expands ChatGPT advertising into more international markets.

The milestone comes months after OpenAI began testing adverts in ChatGPT in the US, adding another potentially significant source of income alongside subscriptions and business services.

From August 31, advertisers in India, Europe, the Middle East and North Africa can buy ChatGPT advertisements directly through OpenAI’s Ads Manager, which had already been introduced in the US.

OpenAI said the self-service system has helped attract small and medium-sized companies, which now account for what the company described as a material part of the advertising business. Revenue from advertisers outside the US is also increasing, although OpenAI did not provide a geographical breakdown.

Advertisements are being shown to people using ChatGPT’s free service and the cheaper Go subscription plan. In April, the company said its initial US advertising operation had exceeded a $100m annualised revenue rate within six weeks of launch.

The rapid expansion puts OpenAI more directly into competition with Google and Facebook owner Meta, which have built enormous businesses around digital advertising.

Advertising could also become increasingly important to OpenAI as it seeks revenue to support the costly computing infrastructure required to develop and operate advanced AI systems.

Reuters reported that OpenAI confidentially filed for a US initial public offering earlier in 2026, with a possible flotation expected in 2027 or earlier.