In 2009, as a part of their “Fun Theory”, Volkswagen replaced a Stockholm subway station's staircase with working piano keys. These keys played tunes as people walked up and down them. Staircase usage (versus escalator usage) increased by 66 percent. We are all in the business of user experience; our users may be staff members, customers, or citizens. Our goal is to ensure the path of least resistance (/most fun) is the same as the desired path. How far can we take the Fun Theory and what are its limitations?