The study of consumers' switching from one service provider to another has a long tradition in economics, information systems, and marketing. The emergence of electronic commerce presents new challenges in understanding consumers' switching intentions in the context of e-commerce in general and online auctions in particular. With the abundance of literature on online auctions, there is a surprising lack of research on auction sellers' intentions to switch from one online auction platform to another. Using the competition between Yahoo!Kimo and Ruten eBay, two leading auction platforms in Taiwan, as the backdrop, we developed a research model and collected empirical data based on this real case to study what factors influence auction sellers to switch to a competing service provider. We find that the higher the procedural switching costs, financial switching costs, relational switching costs, site design quality, or interaction quality, the lower the intention of an auction seller to switch to a competing auction service provider. A higher perceived transaction fee, however, leads to a higher switching intention.