ABSTRACT
The past decade has witnessed a dramatic increase in the number of available modes of interpersonal communication and in the range of quality of these modes in terms of speed, reliability, and flexibility. Many of these modes have experienced substantial price reductions over this same time period; for instance, the price of long-distance telephone service has fallen continuously; both the purchase price of fax machines and the cost of using these machines have declined; online information services such as America Online or CompuServe, which charge a zero price for incremental messages sent to other subscribers to their service and to users of the Internet, have experienced explosive growth in the number of subscribers. All of these modes of communication provide attractive alternatives to traditional postal delivery services supplied by the United States Postal Service (USPS).
