Freemium Generative AI as a Socio-Technical System: Paid Commitment and the Premium Digital Divide in South Korea

Free generative AI (GenAI) services appear to democratize access, but freemium platform models can create post-access stratification after basic connectivity and initial use have been achieved. This article conceptualizes paid commitment to GenAI as an emergent outcome of a socio-technical system composed of platform tiers, user capabilities, task environments, economic constraints, affective feedback, and institutional access. Using a cross-sectional 2025 survey of 2000 South Korean adults aged 18–69, the study models the observed states of non-use, free use, and paid commitment through sequential logit models. Descriptive results show that 70.6% of respondents used GenAI in the previous year, yet only 20.6% of users, or 14.6% of the total sample, paid for access. Practical AI literacy is positively associated with both initial use and paid commitment, whereas critical AI awareness is associated with initial use but not payment. Negative emotions are negatively associated with initial use but positively associated with paid commitment among users, a pattern consistent with vigilant and intensive engagement. The premium digital divide is defined not as a fourth level of the digital divide, but as a tier-mediated extension of second-level inequality that may condition access to later educational, occupational, or civic benefits. Because the data are cross-sectional and combine different GenAI platforms, the estimates are ecosystem-level associations and do not establish causal direction or platform-specific effects.