examples above those with the higher ser will be revealed and listed above all those with a lower ser naturally the higher the ranking listing the more likely to be seen by the end user 40 these examples above relate to rental units such as but not limited to residential rentals and commercial rentals based on monthly rental amounts the system may be used on the rental of any type of product or space referred to as a unit and on the sale of any type of goods referred to as a unit based on total number of goods units combined nou total number of discounted goods units combined nod the total discount amount of all discounted goods units combined tda and the total cost amount of all the goods units combined tca the system may also be used for weekly rentals monthly rentals as in the example yearly rentals and any combinations thereof for rentals all like rentals may be but need not be grouped together i e all monthly rentals are grouped with other monthly rentals of the same duration and all yearly rentals are grouped only with other yearly rentals of the same duration where like rentals are not grouped together but are grouped with groups of differing durations duration of discount dod becomes a standardizing factor to establish relative values for total discount amount tda which when established is the relative discount amount rda and.