The ads will initially appear in the United States for free and lower-tier subscribers, the company said in a blog post outlining its long-anticipated move into advertising.

The integration of advertising has been a key question for generative AI chatbots, with companies largely reluctant to interrupt the user experience with ads.

But the exorbitant costs of running AI services may have forced OpenAI's hand.

Only a small percentage of its nearly one billion users pay for subscription services, putting pressure on the company to find new revenue sources.

Since ChatGPT's launch in 2022, OpenAI's valuation has soared to $500 billion in funding rounds -- higher than any other private company. Some expect it could go public with a trillion-dollar valuation.

But the ChatGPT maker burns through cash at a furious rate, mostly on the powerful computing required to deliver its services.

With its move, OpenAI brings its business model closer to tech giants Google and Meta, which have built advertising empires on the back of their free-to-use services.

Unlike OpenAI, those companies have massive advertising revenue to fund AI innovation -- with Amazon also building a solid ad business on its shopping and video streaming platforms.

"Ads aren't a distraction from the gen AI race; they're how OpenAI stays in it," said Jeremy Goldman, an analyst at Emarketer.

"If ChatGPT turns on ads, OpenAI is admitting something simple and consequential: the race isn't just about model quality anymore; it's about monetizing attention without poisoning trust," he added.

OpenAI's pivot comes as Google gains ground in the generative AI race, infusing services including Gmail, Maps and YouTube with AI features that -- in addition to its Gemini chatbot -- compete directly with ChatGPT.

To address concerns about its pivot into advertising, OpenAI pledged that ads would never influence ChatGPT's answers and that user conversations would remain private from advertisers.

"Ads do not influence the answers ChatGPT gives you," the company stated. "Answers are optimized based on what's most helpful to you. Ads are always separate and clearly labeled."

In an apparent reference to Meta, TikTok and Google's YouTube -- platforms accused of maximizing user engagement to boost ad views -- OpenAI said it would "not optimize for time spent in ChatGPT."

"We prioritize user trust and user experience over revenue," it added.

The commitment to user well-being is a sensitive issue for OpenAI, which has faced accusations of allowing ChatGPT to prioritize emotional engagement over safety, allegedly contributing to mental distress among some users.