Business organizations are using blogs as a conversational technology to help build a community of practice where knowledge exchange and sharing actively take place. This case study examines how Macromedia used blogs to build its developers' communities and become more organizationally effective. Four major types of interactions between the company employees and customers through the blogs are analyzed: socialization, information sharing, help seeking, and teaching and learning. Organizational factors that contributed to the success of such a strategy are also revealed in the study. A model is thus drawn to explain how blogs contributed to the organization's effectiveness by strengthening customer relations, product development, and innovation. Finally, practical suggestions are provided for companies that are considering adopting a blogging strategy for customer relations, product development, and community-driven innovation. (Contains 3 figures and 5 notes.)