Firms have recently sought to maintain a vibrant brand community by incentivizing consumers to generate and spread word-of-mouth (WOM) about their brands via web-based social media. This effort requires an understanding of how consumers are motivated to share their experiences with other consumers. However, despite the widely recognized role of the social network structure in shaping individual’s decisions, there are few studies in the marketing literature examining the association between consumers’ structural properties in brand communities and their WOM activities. This study aims to show the impact of time-varying consumer-specific network topology on consumers’ decision to generate brand-related WOM. Music fandom, a type of a brand community established around a particular media figure, is chosen along with unique data crawled from online social network platform Twitter. This study finds that consumers’ decisions to share brand-related experiences are significantly motivated by the local-level structural properties of a brand community, suggesting that the formulation and implementation of an effective marketing strategy to maintain a vibrant brand community should involve a comprehensive consideration of the opportunities and constraints embedded in the configuration of consumers’ local networks.