Between consolidations and tweaks: Change in infrastructural norms of platformed fan communities on Tumblr

This article examines how platform change shapes the dynamics of platform governance and agency by focusing on infrastructural norms and their implications for vulnerability, collective action, and participation within platformed communities. Infrastructural norms refer to shared expectations about participation that emerge through interactions between users and specific infrastructural arrangements, such as social media platforms. Drawing on empirical material on the Marvel Cinematic Universe (MCU) fandom on Tumblr, the article identifies two processes triggered by platform change: consolidations and tweaks , which respectively reinforce or unsettle existing norms. Examining this empirical setting illuminates how change reshapes participation across both fan-specific cultures and the platform's broader community environment. The analysis focuses on two cases: Post+, a content creation monetisation feature later discontinued, and XKit, a third-party extension that modified Tumblr's interface before being absorbed into the platform's core design. Together, these cases show how platform change makes assumptions about participation visible and gives rise to various forms of contestation. Post+ triggered resistance to platform-led tweaks and was ultimately withdrawn as it generated a user-led consolidation. Meanwhile, XKit demonstrates how user-led tweaks were consolidated through platform appropriation. The findings highlight how moments of platform change expose communities’ dependence on infrastructures they do not control, creating conditions of vulnerability while also opening spaces for collective action. This article contributes to platform studies by introducing infrastructural norms and the interconnected processes of consolidations and tweaks as a conceptual framework for analysing how changing infrastructural arrangements of platforms reconfigure participation, vulnerability, and agency for platformed communities.