Purpose: This study aims to investigate creativity-related determinants of learning in the context of business-to-business services and client-agency relationships. Design/methodology/approach: The research model includes client encouragement, agency creativity, campaign creativity, and perceived performance. The study involved conducting a questionnaire survey in 150 publicly-traded companies in South Korea. Findings: The results show that client learning from agency services is the result of the creative process of the agency and the creativity of the service outcome itself. Client learning from marketing services also varied depending on different performance ratings. Originality/value: The study elucidates client learning as the central process of value co-creation in the brand value chain. It produces several unique findings and managerial takeaways for building up better co-creation environments in the context of business-to-business services. (Contains 1 figure, 2 tables, and 1 note.)