The digitalization of fandom and fan culture has become significant topic in recent studies, yet there is a lack of examination of the nuance between specific fan performance and the affordance, infrastructure and architecture that constitute it as it is today. In this article, I examine how digital fandom involves the platform algorithm and the logic of data contribution, affectively engaging fans to participate in increased data labour. Depicting online fandom on Weibo, a massive Chinese social media platform, I portray the data-ization of online fandom in China, arguing that the traffic data has been dematerialized as new affective object in fan–object relations, while digital fan culture has been constructed into a type of algorithmic culture.