The book analyzes the role of the fan within the ecosystem of a sports brand, where the club and the athlete form an interconnected structure influencing consumer attitudes and behaviors. The author demonstrates that fan engagement is multidimensional and relational, and that its intensity toward one brand shapes the perception of the other. 
The study combines a theoretical framework with empirical research, in which two engagement measurement scales were developed and validated: one for the team and one for the athlete. The use of structural equation modeling allowed for the reconstruction of relationships between constructs and the assessment of their impact on match attendance and media consumption. 
The findings reveal a strong interdependence among engagement components and highlight the significance of the triadic fan–team–athlete relationship. The book provides both a theoretical contribution to the study of brand ecosystems and practical guidance for sports organizations designing communication initiatives and strategies for building relationships with fans.