The functional approach considers the jobs that must be done, but not the agency that performs them. Analyzing functions of various middlemen is helpful in evaluating marketing costs. Retailing is more costly than wholesaling. Functional approach points up the greater complexity of retailing. Cost comparisons are useful only when they are related to the job done. The functional approach is also useful in understanding the difference in marketing costs of various commodities. For example, a perishable product is more costly to market than a less perishable product. The difference may be because of the greater difficulty in the performance of the transportation, storage and risk bearing functions. Probably of greater importance, the breaking down of a complex marketing task into its component functions greatly aids in efforts to improve the performance of the marketing machinery