This article discusses the politics of differentiated integration in European Justice and Home Affairs from a theory of clubs and transaction-cost perspective. By way of comparative analysis of two cases the Schengen regime and the Pruem Treaty I outline the main stages of a differentiation club's career. Analyzing the costs and benefits at stake for club members and non-members allows me to get a tight grasp of the politics of differentiated integration at the different stages. The club's trajectories reveal, however, that contingencies and ad hoc solutions interfere with strategic calculations to a high degree. The article concludes that incorporation efforts necessarily lead to pick-and-choose situations that preclude full uniformity; consequently, outside treaty clubs always lead to á la carte fragmentation. Moreover, time pressure and bargaining dynamics in incorporation efforts preclude effective search for efficient policy solutions; hence, smaller club agendas generate less incorporation problems.