In late 2011, when I won a fitbit in a white elephant party, I came to the awful realization I only walked 4,000 steps per day. Over the next 2 months, I gradually upped my steps to 20,000 steps a day and lost 13 pounds.

I am now known as the fitbit fascist by my friends because whenever someone kvetches about their weight, I offer to buy them a fitbit. I have followed through on this twice. In both cases, the victims wore their fitbits for several months and then gave up on increasing their daily step count, removing their fitbit so they'd stop being reminded that they were only walking 2,000-3,000 steps per day rather than do something about that.

Figure out why that happens and I think you'd drastically increase how to increase the mass market appeal of quantified self wearables like this.