For three years, OpenAI has generated most of its revenue from people paying $20 a month for subscriptions to ChatGPT. This year, it is forecasting a massive shift, expecting a cheaper, ad-supported tier will both draw new users and cause tens of millions of its paying subscribers to downgrade, according to previously undisclosed projections.

The company’s hope is that it will make more money by selling ads shown to more users than relying on the existing flagship monthly subscription service, which is called ChatGPT Plus.

OpenAI at the start of this year forecast that consumer subscribers to ChatGPT Go, which costs $8 a month in the U.S. and around $5 monthly in other countries such as India, would surge about 36 times to 112 million this year. As a result, leaders have projected that the number of subscribers to ChatGPT Plus will fall 80% to about 9 million. Users of the most expensive Pro plan will double but will still make up less than 1% of the total, the forecasts said.