Advertising is the only cost element not fitting the explanation of a variable cost given in the first paragraph. Advertising costs are set by management decision rather than being an "automatic" cost item like sugar or packaging. In this sense, advertising is like route salesmen's expense. For our company, however, management has decided that the allowance for advertising expense is equal to $.06 per litre for the actual number of litres sold. This management decision, therefore, has transformed advertising into an expense which is treated as variable for profit planning purposes.