Electronic business has brought many success stories as well as failures. Intermediaries are a particularly interesting application domain: on the one hand, they are given opportunities by electronic business to reinvent their value logic, while on the other they are threatened by opportunities for customers and suppliers to deploy electronic business to do business directly. Designing for Acceptance addresses the acceptance of electronic intermediaries by studying the design of the exchange. For example, should a web catalogue provide price information and should it consider an extension with transaction functionality? Developing the right exchange design is a complex undertaking because of the many design options and the interests of multiple actors that need to be taken into account. Four cases were studied: Tapestria (interior fabrics), SeaQuipment (maritime products), Meetingpoint (insurances) and Voogd & Voogd (insurances). The results are an exchange design model and patterns that are derived from numerous case lessons and are supported by insights from theories on electronic intermediaries, acceptance and business design. The exchange design model offers a systematic insight into generic exchange design themes that are relevant to the interests of customers, intermediary and suppliers. Exchange design patterns discuss specific trade-offs with respect to one or more themes. This study contributes to current knowledge by providing support for balancing interests in exchange design beyond simple prescriptions like "creating win-win situations". The exchange design themes and patterns are convenient instruments that offer constructive support for developing a vague electronic business idea into a concrete service concept.