This paper presents the concepts, definitions, issues, and solutions that revolve around the adoption of capacity-driven Web services. Because of the intrinsic characteristics of these Web services compared to regular, mono-capacity Web services, they are examined in a different way and across four steps denoted by description, discovery, composition, and enactment. Implemented as operations to execute at run-time, the capacities that empower a Web service are selected with respect to requirements put on this Web service such as data quality and network bandwidth. In addition, this paper reports on first the experiments that were conducted to demonstrate the feasibility of capacity-driven Web services, and also the research opportunities that will be pursued in the future.