A purchase is an exchange of value: I give you $5,000 in exchange for a backyard storage shed. You pay $50,000 for a piece of equipment, and in exchange, the dealer delivers and installs the equipment and teaches you how to run it. My wife pays the grocery store $100, and in exchange, the store allows her to walk out of the store with a cart of groceries. When we pay money but don’t think that we received the same or equal value in return, we feel cheated.
When business owners spend money on marketing, they worry about not getting anything valuable in return. That’s because it’s often hard to see what we got in exchange for our money. Decades ago, businessman John Wanamaker said, “I know half of my advertising dollars are wasted. I just don’t know which half.”