Beeminder
Pledge real money against your goals; go off track and you lose it.
Beeminder is built on a single behavioral principle: loss aversion, the observation that losses hurt more than equivalent gains feel good. You set a goal, pledge an amount of money you are willing to lose, and report progress against the goal’s data. Drift off track and the pledged money starts going away.
It is gamification with real stakes rather than symbolic ones, and it selects for a particular kind of user: people who know incentives work on them and want to point that machinery at their own goals.
The design lesson: negative stakes are the sharpest motivational tool and the easiest to misuse. Beeminder works because users explicitly self-impose the stakes; imposing them on users would be hostile design.
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