use in dollars per hour and estimated usage is the customer 39 s estimate of the amount of time that will be spent using an isp 39 s services during a month for the three eligible plans listed in table 2 the emc can be calculated by using the estimated usage information that the customer entered in step 825 or was determined in step 1070 of the business profile method and by using the monthly cost and usage cost that were retrieved from the commodity database in step 865 assuming that the customer entered 30 hours month in step 825 the emcs for the eligible plans listed in table 2 are next the estimated cost is adjusted by the utility functions and other cost equations stored in the optimization database 350 the process of calculating the utility functions and associated constants will be described now with reference to fig7 the process begins with the identification of the key parameters associated with a commodity category as shown in step 610 these key parameters are parameters that affect the customer 39 s decision about a commodity and may include features performance or quality characteristics of a particular commodity for example in the case of an isp plan the key parameters are connection speed disk space which the customer for example may use for a web site the quality of the connection number of email accounts and the contract length.