According to the analyst, Apple Watch took less than six years to cross the 100 million milestone. Some of the data points revealed by the analyst claim that 30 million new users started using an Apple Watch in 2020, which was way more than the users in 2015, 2016, and 2017 combined. "At 100 million users, the Apple Watch is Apple's fourth-largest product installed base behind the iPhone, iPad, and Mac. At the current sales trajectory, the Apple Watch installed base will surpass the Mac installed base in 2022. Surpassing the iPad installed base will take longer and likely be measured in a number of years based on the current sales trajectory," the analyst said in a statement.