The objective of this study is to propose a conceptual model that considers separately the cognitive and affective aspects of brand relationship quality in online services and investigate their mediation effects on the link between brand evidence (e-service quality; brand value, and self-image congruence) and brand loyalty. To test the proposed model, a survey of 971 customers of online booking platforms was conducted using a structured questionnaire and established scales. Data was analyzed with PLS–SEM. Results indicate that all brand evidence constructs significantly affect both aspects of brand relationship quality. The affective aspect of brand relationship quality is the most important direct determinant of brand loyalty, followed by the cognitive aspects and brand value. E-service quality and self-image congruence affect both brand relationship quality aspects only indirectly, through brand loyalty. This means that brand relationship quality aspects partially mediate the brand value-brand loyalty link, while they fully mediate the effects of e-service quality and self-congruence on brand loyalty. Finally, implications of these findings and directions for further research are provided at the end of the paper.