Most of the research on mergers and acquisitions has focused on the organization(s) undergoing a merger. Numerous studies have observed a common syndrome marking the postacquisition period. Poor organizational performance is one of the regular symptoms of this syndrome, yet little attention has been addressed to the role of customers, whose patronage is a prime determinant of economic performance, and competitors. A case study was developed of a merger of two local organizations. Data were collected from customers and competitors, and the analysis led to a feedback loop model of customer and competitor roles in postmerger performance. Among the important observations are: (a) organizational change causes customers to change vendors, (b) the announcement of a merger fuels efforts by competitors to “steal” market share, and (c) organizational change leads to more organizational change. These dynamics are, furthermore, a function of communication between the merging organizations and their customers.