The introduction of the internet originated not only the establishment of an alternative channel for the marketing and selling of products, but even more importantly, it serves as a platform to set up B-to-B E-marketplaces. This development enables buyers and sellers to innovate entire business processes. However, in order to gain sustainable and tangible success, a company needs to thoughtfully analyze the different concepts of B-to-B E-marketplaces as there are many examples where the introduction of such marketplaces had non-intended negative consequences. Evi Hartmann discusses the following research questions: What is the relation between a given purchase situation and the characteristics of a B-to-B E-marketplace? Can a fit between the two be defined from a relationship perspective? How does the interplay between the purchase situation and the B-to-B E-marketplace characteristics influence the success of a supplier relationship? The author presents a theoretical framework, which has been empirically tested in the German chemical industry, illustrates the managerial implications and shows the necessity of future research.