Recent advances of virtual networking technologies are gradually forcing companies to focus their knowledge management efforts to external knowledge resources, in order to complement their existing knowledge bases, find expertise, but also harness collective intelligence that is dynamically produced in the virtual environment. Access, exchange and co-creation of customer knowledge is of central importance for companies in this context, as customers who take advantage of Web 2.0 connectivity and social networking tools are gaining importance as competitive and cooperative knowledge actors in companies’ C-Business value networks. In this paper the authors attempt to cover important issues concerning customer knowledge flows between companies and customers through virtual interaction and the important factors that determine value-adding relationships of cooperation with customers for effective knowledge co-creation. They emphasize the need for the formation of a strategic co-opetition perspective for managing these relationships. In this direction, the authors present a theoretical framework that describes Customer Knowledge Management within a C-Business context.