Value-of-service pricing is sometimes defined as charging what the traffic will bear. In actuality,this phrase can assume two meanings. First, it can be used to mean that prices are set so that on each unit the maximum revenue is obtained regardless of the particular costs involved. That is, no service should be charged a lower price when it could bear a higher price. The second meaning, which can be more conveniently expressed in a negative form and which is germane to this discussion, is that no service should be charged a price that it will not bear when, at a lower price, the service could be purchased.