Sharing with CNBC, analyst Toni Sacconaghi from Bernstein, a market research firm, estimates that Apple could sell 85 million AirPods by 2020, which will generate sales of up to $15 billion.He also estimates that Apple's revenue from selling AirPods has reached $6 billion this year and could double next year. If it continues at the same growth rate in 2021, AirPods could become Apple's third-largest business.However, after a few more years, Toni Sacconaghi believes that AirPods sales may decline relatively quickly as the market gradually reaches the saturation point.Toni Sacconaghi emphasized that the AirPods saturation rate is as fast as iPhone sales and the revenue growth rate of AirPods will drop sharply from 2021 and 2022. Specifically, the growth rate can be reduced to only one digit or lower.Apple certainly understands this problem, so it may actively upgrade AirPods with more exciting new features. While the growth rate is unlikely to be stable, in the long run, Apple may encourage customers to upgrade on the basis of periodic product launches.Toni Sacconaghi is not the only analyst who believes in AirPods sales growth prospects. Earlier, Dan Ives, an analyst at WedBush, estimated that Apple could sell 3 million AirPods on Black Friday and Cyber ​​Monday.Meanwhile, analyst Asymco believes that AirPods could soon reach $4 billion in revenue each quarter, surpassing the peak of iPod sales in 2007.These predictions are entirely based when AirPods sales are impressive growth. For example, the AirPods Pro model has sold out at the Apple Store and at many online retail stores.In 2019, Apple's stock rose more than 77%, bringing the company's market capitalization to $1.2 trillion.