Smartwatches and fitness trackers are about more than athletic pursuits and telling the time. Market penetration has grown, and adoption has expanded beyond the earliest wearables users. The US has higher market penetration than the UK or Germany, and Japan has less than the other three.
This MetaFAQs reports on the percentage of online adults in the US, Germany, UK, and Japan that regularly use a smartwatch or fitness tracker, further split by age group in each country.