New Delhi, Aug. 31 -- OpenAI's advertising business has reached a $1 billion annualised revenue run rate, marking a rapid rise for a business that began testing ads on ChatGPT only about 200 days ago. The milestone comes as the artificial intelligence company expands advertising to more markets and prepares for what could be one of the largest technology initial public offerings.

OpenAI said the advertising business is now part of a broader revenue mix that includes enterprise products, consumer subscriptions and usage-based application programming interfaces. The company is also seeking to demonstrate the strength and diversity of its business as it faces scrutiny over its reported $852 billion valuation.

OpenAI began testing advertise...