Starting at the Stanford Center for Societal Networks with Prof. Balaji Prabhakar in 2011, I have been involved in developing and deploying incentive schemes: Steptacular for encouraging exercise among Accenture employees, and TravelSmartRewards for Singaporean train commuters, and others.
When you collect fine-grained long-term data about people, you can learn so much about why people behave as they do, and when they are prepared to change their behaviour. Social currency is more important than money: people engage when they can engage with their friends, and models of Homo economicus are far off the mark. Maybe astrology gives a better model? 😉