4.9 The major portion of retail sales is paid for when the customer purchases the goods. Because credit sales are comparatively uncommon, accounts receivable are a smaller percentage of sales than they are in other industries. This shows up as a low collection period or, equiva- lently, as high turnover of receivables. Computer software companies do not have to maintain a large inventory of finished prod- uct awaiting sale. Often, they can deliver some product electronically as it is ready. In addition, software development does not require large inventories of inputs that need to be assembled into a final product. Therefore, inventories compared to cost of goods sold will be lower than is the case in other industries, and this is reflected in high inventory turnover ratios.