A system for selling products and services over the Internet, or other wide area network, comprises a knowledge base and a knowledge base configurator both executing on a network-connected server hosted by the enterprise offering products and/or services. A GUI user interface application is downloaded from the server to any platform used by a client wishing to purchase products or services. Having downloaded the user interface, the client can manipulate the configurator over a data link between the client's station and the server to configure the knowledge base to define products and/or services to be orders, and can complete orders. A preferred implementation is with the server as an enterprise-hosted server connected to the Internet, and clients as users connected typically through Internet Service Providers to the Internet.