While customer management has become a top priority for practitioners and academics, little is known about how managers actually make customer management decisions. Our study addresses this gap and uses the adaptive decision maker as well as the fast and frugal heuristics frameworks to gain a better understanding of managerial decision making. Using the process-tracing tool MouselabWEB, we presented sales managers in retail banking with three typical customer management prediction tasks. The results show that a majority of managers in this study are adaptive in their decision making and that some managers use fast and frugal heuristics. Usage of adaptive decision making seems to be mainly driven by low objective task difficulty, the use of fast and frugal heuristics by experience. While adaptive decision making does not impact predictive accuracy, usage of fast and frugal heuristics is associated with proportionally greater use of high predictive quality cues and a significant increase in accuracy. Hence, the existing skepticism concerning heuristics should be questioned.