Comparing Contribution Margin Percentages Following are actual statements of operating income for Microsoft and Procter & Gamble (in millions): Microsoft Procter & Gamble Revenues $60,420 Net sales $83,503 Cost of revenue 11,598 Cost of products sold 140,695 Research and development 8,164 Selling, general, and administrative expenses 25,725 Sales and Marketing 13,039 General and administrative 5,127 Operating income $17.083 Operating income $22,492