When Platforms Displace Routine Relationships: Electronic Service Quality, Behavioral Predictability, and the Dual-Threshold Logic of Customer Loyalty in B2B Digital Service Platforms

Business-to-business digital service platforms increasingly automate routine information and coordination tasks once handled by account managers, yet suppliers keep investing in dedicated contacts and proactive communication. This raises a resource allocation question: does routine relational service investment retain incremental loyalty value as platform electronic service quality improves? Drawing on transaction cost economics, uncertainty reduction theory, and service quality theory, this study examines two electronic service quality thresholds—an enabling threshold below which platform quality constrains loyalty formation, and a substitution threshold beyond which routine relational investment ceases to generate loyalty increments through behavioral predictability and satisfaction. Two-wave data from nearly five hundred enterprise clients across more than twenty business-to-business platforms were analyzed using partial least squares structural equation modeling with disjoint two-stage estimation, two one-sided tests, and necessary condition analysis. The enabling threshold lies well below the substitution threshold, supporting a three-zone service structure. Complex exception-handling capability retains positive associations with satisfaction regardless of platform quality. These findings reframe electronic service quality as a boundary condition for relational resource allocation rather than a direct antecedent of satisfaction, offering implications for how service firms restructure account manager roles as platforms mature.