A central tenet of electric power industry deregulation is that the delivery of electric power (a service) must be decoupled from the purchase of the power itself (a product) and priced and contracted separately. Transmission of electricity must be offered and priced separately from the power itself, and delivery of power must stand on its own as a business. Regardless of the precise nature of the deregulated system's rules and structure, this means that transmission system operators need to know the actual operating costs of providing transmission services to their customers. Here, the authors argue that such analysis of costs and cost flow will become as routine and sophisticated as the analysis of electrical performance is at the present.