OpenAI faces stark doubts about ChatGPT ads. It's beginning the long fight to prove them wrong.

OpenAI CEO Sam Altman. Brendan Smialowski / AFP via Getty Images OpenAI has lofty goals for ChatGPT's ads business, an attempt to monetize the blockbuster app. The product is still rudimentary, advertisers said, though it's changing every week. OpenAI's ad revenue projections aren't logical, one analyst told Business Insider. OpenAI badly wants a piece of the advertising empires that Google and Meta built, and it has a lot of catch-up to do. The AI startup began selling ads on its…