Supplementary file 1_Channel membership mechanisms in UGC platforms: content creation, revenue structure, and platform incentives.pdf

However, channel membership may also reshape creators’ allocation of effort, thereby affecting content supply, monetization strategies, and platform profitability. To examine the implications of channel membership for the sustainability of UGC platform ecosystems, this study develops a three-stage game-theoretic model involving the platform, content creators, and consumers, and compares two representative channel membership mechanisms: content-partition membership, in which certain content remains permanently exclusive to members, and time-partition membership, in which members receive temporary early access before the content becomes freely available.

The results show that UGC platforms exhibit interior optimal commission rates on both the advertising and subscription sides. Moreover, channel membership does not necessarily reduce the quality of free content; its effects depend on the membership mechanism and market conditions. Content-partition membership is more suitable for environments characterized by strong user willingness to pay and high-value content, whereas time-partition membership is better suited to platforms where advertising revenue plays a more important role.