This paper investigates whether monetary incentives can be used to promote healthier sleep habits. We collected detailed data drawn from wearable sleep trackers and randomized monetary incentives to sleep. Subjects in the treatment group significantly increased their sleep duration. There is evidence of demand for commitment and sophisticated hyperbolic discounting behavior, self-serving bias and some evidence of habit formation effects. The size and the frequency of the incentives are crucial to sustain the healthy behavior after the intervention. Effects are concentrated among those reporting insufficient sleep at baseline. Incentives to sleep improved not only sleep duration, but also sleep quality.