A simple approach, called PMP (Paris Metro Pricing), is suggested for providing differentiated services in packet networks such as the Internet. It is to partition a network into several logically separate channels, each of which would treat all packets equally on a best effort basis. There would be no formal guarantees of quality of service. These channels would differ only in the prices paid for using them. Channels with higher prices would attract less traffic, and thereby provide better service. Price would be the primary tool of traffic management. PMP is the simplest differentiated services solution. It is designed to accommodate user preferences at the cost of sacrificing some of the utilization efficiency of the network.