This study examines customer brand co-creation in interactive media environments through the lens of Social Exchange Theory. It investigates how brand interactivity and perceived ease of use influence consumer participation, with relationship quality and brand knowledge serving as key mechanisms. Drawing on survey data from active social media users, the findings show that interactive brand features enhance customer engagement by fostering stronger relational bonds. These relationships, in turn, encourage co-creative behaviors such as content sharing, feedback provision, and collaborative design. The study also reveals that participation in cocreation deepens brand knowledge, particularly among consumers with high brand attachment. By integrating cognitive and relational perspectives, this research clarifies how value is jointly constructed in digital brand ecosystems. The results underscore the importance of designing interactive platforms that support reciprocal exchange and meaningful consumer involvement. This paper contributes to brand management and digital marketing literature by empirically validating the role of social exchange dynamics in shaping contemporary co-creation practices....