Web services are rapidly becoming the technology of choice for integrating distributed application components in heterogeneous computing environments. In this paper, we present a novel e-commerce prototype application that itself would not be feasible without the leverage provided by underlying Web services technologies for flexible design and rapid prototyping. The application is a Model-driven Service Brokerage that allows service providers to model, advertise, validate, and create a wide range of services (e.g. Internet access services such as DSL, and Cable, Video-on-demand, etc) in an open marketplace in an automated fashion. The application answers real needs expressed by today's large Service Providers and goes beyond the current state-of-the-art in online communication marketplaces. It consists of several functional components - i.e. a service dependency modeling tool, brokerage engine, location services, and workflow engine - that have been independently developed on diverse platforms, e.g., J2EE, .NET. To efficiently integrate these components, we have designed a distributed Web services architecture, in which one Web Service functions as a "hub" between previously disconnected components, another works as a "wrapper" of legacy data systems, while another "orchestrates" invocations of these services. Use of Web services has enabled parallel and independent development and testing, greatly increasing productivity and reducing time to get the system operational. It has also fostered the development of new Brokerage features, which would have been difficult to plan without first experimenting with a "live" system.