"Economists classify advertising into two broad types: informational advertising and image advertising. There is a third, lesser known type of ad called commodity advertising. These ads focus on generic products like agricultural commodities. Well-known examples are the "California Raisins," "Got Milk?" and "Real California Cheese" campaigns.
The economists calculate that each dollar spent on advertising agricultural products like eggs, milk, beef, prunes and almonds yields $3 to $6 of additional revenue to producers."
If you want to learn more, there's a fairly expensive book on Amazon called Commodity Advertising. The review from a specialized site says: "Over $750 million are spent annually to promote agricultural commodities. Here, for the first time, is a book that explores how that advertising money is raised and spent, the economic effectiveness of commodity promotions, and the differences between commodity and brand advertising."
