According to a recent survey by IDC, the Apple Watch was the highest selling smartwatch in the last quarter and the entire year of 2017. Apple shipped an estimated 8 million units in Q4 of 2017 compared to 5.1 million in the same quarter in 2016. Overall market share in Q4 went from 14.4% behind Fitbit and Xiaomi in 2016 to 21% in 2017, ahead of everybody else. As for the whole year, Apple shipped 17.7 million units in 2017 versus 11.3 million in 2016. Total market share went from 10.8% in 2016 to 15.3% in 2017. But here's the real kicker; the numbers you just read were...
Source: https://www.gsmarena.com/apple_watch_outsells_all_other_smartwatches_combined_in_2017-news-29930.php