OpenAI CEO Sam Altman arrives for a meeting at the White House in Washington, D.C., U.S., July 30, 2026. Nathan Howard | ReutersOpenAI on Monday announced that its advertising business has hit $1 billion in annualized revenue run rate, a milestone that the company is touting as proof of its "diversified business model." The artificial intelligence company is gearing up for what is expected to be a massive initial public offering, and is under pressure to justify its $852 billion valuation to inv...