OpenAI said its advertising business has reached a $1 billion annualized revenue run rate, adding a new income stream alongside enterprise services, consumer subscriptions and API billing. The company said advertising has become a meaningful revenue driver as it supports its roughly $852 billion valuation and a potential IPO. OpenAI began testing ads in ChatGPT in the U.S. in February and has since expanded ChatGPT Ads to more than 40 countries. Self-serve ad buying is now available in regions including India, Europe, and the Middle East and North Africa. Ads are shown to ChatGPT Go subscribers and free users across what OpenAI said is about 1 billion weekly active users. The company said ads will be clearly labeled, will not affect ChatGPT responses, and advertisers will not be able to access users' private chat content.