> Second, is when at the end of the day your are close to your target, its easy to convince yourself to go for a little walk to reach the target.
Having an external locus of control can make a huge difference for some people when it comes to exercising more or eating better. It helped for me.
> ...but the device and app work great for what they do.
That was NOT my experience with the app. I think it's pathetic they decided to try to be their own ecosystem instead of being part of HealthKit, but that's not their big sin.
In the two or so years I used a Fitbit the app only got worse. Food logging was repeatedly changed, losing features, and getting harder and harder to use. They later changed exercise entry to make it work better for runners and harder for everything else. They took FOREVER to update from iOS 6 style interfaces to iOS 7.
But the big thing, the KILLER thing, was that all my data was corrupted by a bug they knew about and refused to fix. There was an option to adjust your daily calorie goals based on activity (or something like that). Having that on used to be the default, but it caused all sorts of problems. I only found that out after noticing tons of my old data had almost exactly the same calorie count each day. Like within 10 calories.
After numerous support emails (their support system was terrible) I was finally told to turn that option off. They knew it caused issues, that's why they started turning it off by default. But they didn't tell people who had it on about the issues it caused or detect if they were hitting the bug. They fixed it for new users and left older users screwed.
So I have 2+ years of useless fitness data in FitBit. It doesn't matter if it can be exported for free or put in HealthKit, the data is junk.
I don't remember having a single positive interaction with FitBit over support or other problems. They were at best neutral. My opinion of them went lower and lower and lower over time.