Firms that sell highly differentiated consumer goods, such as over-the-counter drugs, perfumes, soft drinks, razor blades, breakfast cereals, and dog food, typically spend between 10 and 20 percent of their revenue on advertising. Firms that sell industrial products, such as drill presses and communications satellites, typically spend very little on advertising. And firms that sell homogeneous products, such as wheat, salt, sugar, and crude oil, spend nothing at all.For the economy as a whole, about 2 percent of total firm revenue is spent on advertising.