Abstract: E-commerce applications have imposed a huge set of new paradigms and challenges to the entire soft- and hardware community. In this paper, we focus on the changes and challenges that data warehouses already face in this context. SAP provides with its Business Information Warehouse (BW) a basic infrastructure element for its e-commerce platform mySAP.com. We will summarise some of the experience that we have made when adjusting and extending BW to fit the requirements of mySAP.com.