Gizmodo | Fitness Trackers Use Psychology to Motivate Couch Potatoes.

When it comes to fitness trackers, the psychology behind them is just as important as the technology inside them. Gadgets like the Nike+ FuelBand, Fitbit Ultra and BodyMedia Fit Link use accelerometers, altimeters and algorithms to track everything from how many steps you took to how many calories you burned. By providing this data instantaneously, and in some cases allowing you to share it via social media, they do more than inform. They reinforce, motivate and reward by turning exercise into a game. Continue.