Paris' Velib system found that people didn't like riding up some of the steeper hills: "See, Paris has a handful of steep hills. The Montmartre neighborhood, f

Paris' Velib system found that people didn't like riding up some of the steeper hills: "See, Paris has a handful of steep hills. The Montmartre neighborhood, for example, is perched at the top of a rise some 450 feet above the Seine. Taking a bike down the hill has a certain obvious appeal, but riding back up to the top... not so much." "Over the summer, though, the good people of Vélib added a simple behavioral incentive to the system: Return your bike to one of 100 stations perched over 60 meters above the rest of the city, and 15 minutes of free riding is added to your account." http://globalmoxie.com/blog/velib-bonus~print.shtml http://globalmoxie.com/blog/velib-bonus~print.shtml I think it's neat they managed to put some game mechanics in to the pricing model to encourage users to make the whole system work better for other users.