Every Monday morning, Pathé Theaters in the Netherlands decides which movies in its cinemas to retain and which to replace. It must choose replacement movies from those available at that time. We implemented the SilverScreener model, a mathematical-programming system [Swami, Eliashberg, and Weinberg 1999] to help Pathe ́ managers make those decisions for one six-screen theater and tested its performance against the performance of two unaided similar multiscreen cinemas. Using Pathe ́’s historica ldata, manageria ljudgment, and theater-specific factors, we developed an attendance-forecasting system. While a fully controlled experiment was not possible, the revenues at the theater using the SilverScreener recommendations were higher than those at the two comparable theaters. Managerial attitudes towards the modeling system improved after implementation of SilverScreener.