From "I created this" to "I love this": How interactivity and output diversity shape continuance intention in GenAI-enabled product customization.

Generative AI (GenAI) is increasingly embedded in product customization, yet little is known about how its affordances sustain user engagement beyond initial adoption. Drawing on Self-Determination Theory, this study examines how interactivity and output diversity relate to continuance intention through perceived design agency and customization satisfaction. Using an explanatory sequential mixed-methods design, we first surveyed 829 participants with recent GenAI experience after they completed a standardized exploration of a GenAI-enabled product customization platform, and then conducted semi-structured interviews with 13 participants to interpret the non-significant direct association between perceived design agency and continuance intention. Both affordances were positively associated with perceived design agency, customization satisfaction, and continuance intention. Perceived design agency, however, had no significant direct association with continuance intention; instead, the agency-continuance association followed an indirect-only mediation pattern through customization satisfaction. Interview findings further showed that felt authorship supported continued use when accompanied by a satisfying, feasible, and meaningful customization experience. These findings position perceived design agency as an upstream psychological mechanism rather than a direct driver of continuance intention and identify an affordance-agency-satisfaction pathway through which GenAI-enabled customization may support sustained use.