Fandom platforms, born from the combination of the media industry and fandom culture, are changing the center stage of fan activities, creating a new landscape for the cultural content industry. Fan activities, previously distributed across various channels, are now concentrated on fandom platforms, with a majority of them being conducted through them. The study explores ways to define fandom platforms, how fans respond to them, and their industrial possibilities and limitations, and discusses the future prospects of fandom platforms as well. Through these analyses, the study aims to understand what impact fandom platforms could have on the cultural content industry and the resulting industrial changes.