PurposeThe purpose of this paper is to explore and examine the different word-of-mouth (WOM) acceptance and diffusion in social brand communities according to the level of self-monitoring.Design/methodology/approachA web-based experimental design was used. The design consisted of three-mixed design of 2 (type of social networking sites) × 2 (type of online brand communities) × 2 (self-monitoring). ANOVA analysis was conducted.FindingsFindings indicate that the differences in acceptance and diffusion of WOM according to online brand community type, and there was a significant three-way interaction effect. Specifically, people who have high propensity to self-monitor showed greater WOM acceptance in a consumer-driven community in either type of social networking sites while people who have low propensity to self-monitor showed greater WOM diffusion in a consumer-driven community only in interest-based social networking sites.Practical implicationsAn important implication is that the social networking sites where brand communities can be placed should be chosen with the full consideration of different desires consumers have in terms of their level of self-monitoring to increase WOM effects.Originality/valueThis paper proposes the self-monitoring tendency as the key factor that predicts WOM effects with revealing the optimal combination of types of social networking sites and online brand communities that is most preferable for consumers with different self-monitoring level.