In this paper, we discuss a new relation between customer and firm as DCM(Demand Chain Management). The firm applies customer needs information to product development and service enhancements. This enable firms to get long run customer. The DCM concept differs in product choice from a SCM concept. According to the DCM concept, a firm can get customer needs information from virtual community. We develop a model of the DCM with respect to virtual interactions among participants. As a result of simulation, we discuss the relation among product multiplicity, customer satisfaction, and customer segmentation.