I wonder how well the secondary market could be used to gauge the long term appeal. Would people sell it because they stop using it or it is like those skinny

I wonder how well the secondary market could be used to gauge the long term appeal. Would people sell it because they stop using it or it is like those skinny jeans you keep because one day you will use it again? I will say that it was neat and then lost interest, but later once I had some "fitbit friends" the gamification went up a major notch as has the stickiness. But within a few years either FitBit bands will turn into watches or users will replace their FitBit with a watch. So from the FIT perspective it hardly seems like a stable investment especially at the current market cap.