Abandonment rates for smart watches and fitness trackers are about 30%

"The abandonment rate of smartwatches is 29 percent, and 30 percent for fitness trackers, because people do not find them useful, they get bored of them or they break, according to a survey by Gartner, Inc.
"Dropout from device usage is a serious problem for the industry," said Angela McIntyre, research director at Gartner. "The abandonment rate is quite high relative to the usage rate. To offer a compelling enough value proposition, the uses for wearable devices need to be distinct from what smartphones typically provide. Wearables makers need to engage users with incentives and gamification."
The 2016 Gartner Personal Technologies Study surveyed 9,592 online respondents from Australia, the U.S. and the U.K. between June and August 2016, to gain a better understanding of consumers' attitudes toward wearables, particularly their buying behavior for smartwatches, fitness trackers and virtual reality (VR) glasses.
According to the survey, smartwatch adoption is still in the early adopter stage (10 percent), while fitness trackers have reached early mainstream (19 percent). Only 8 percent of consumers have used VR glasses/head-mounted displays (excluding cardboard types)."
Source:  Gartner, 7th December 2016