Purpose: The purpose of this study is to provide a better understanding of customer brand engagement (CBE) by proposing and empirically testing a model of antecedents and consequences of CBE for user-initiated online brand communities (OBCs). Design/methodology/approach: The model is tested using a sample of 584 participants in two relevant OBCs created and managed by brand fans. Specifically, data were collected from two communities in the photography products category: Nikonistas and Canonistas. Findings: The results indicate that community and brand identification positively and significantly influence CBE. Furthermore, the supporting role of OBCs’ moderators facilitates CBE and moderates the influence of community identification on CBE. Regarding the outcomes of CBE, the results show that higher levels of engagement are positively, directly and significantly associated with favorable intentions towards the brand and the community. These effects are then mediated by brand affective commitment. Research limitations/implications: The study has been conducted in two Spanish OBCs of two specific high-involvement products category: it is cross-sectional and focuses on a limited number of antecedents and consequences. Practical implications: Evidence from this research supports and emphasizes the potential that these platforms have for brand management such that firms’ resources could be best allocated on those elements that lead to superior CBE. Originality/value: The study endorses the role of CBE in fostering brand and community-related favorable outcomes in the context of user-initiated OBCs. It shed lights on the potential that these online platforms have for brands and on the role that brand management should play in digital contexts that are outside the direct control of the company.