Service businesses are increasingly facing more demanding customers as a result of a shift in power from the service providers' side to the customers' side. Related literature predominantly examines the negative side of this ongoing trend, while overlooking the positive side. The major aim of this paper is to examine how frontline employees — investment account managers — deal with the ongoing increase in customer demandingness. To address this, we draw on adaptability performance theory to test the facilitating effect of frontline employees' post-transaction service behaviors (SBs) — diligence, inducements, information communication, sportsmanship, and empathy — as a means of adaptation to higher levels of customer demand. Findings indicate that frontline employees adapt most of their SBs' intensities to match customers' demands. The results show that some SBs actually increase the effectiveness and efficiency of frontline employees' service performance, leading to an increase in customer value and satisfaction. Customer value is found as a mediator in some of the relationships between SBs and customer satisfaction. Contrary to the conception of the negative outcomes of customer demandingness, service firms need to consider taking advantage of customer demandingness by stressing the role of frontline employees in adapting to customers’ demands.