Usually, a company that sends out direct-mail advertisements has good reason to think that the person to whom the advertisement is sent would be more interested in the product than would the average person. Most of the products purchased in response to direct-mail advertisements would be purchased even without the direct-mail advertisements. A person who receives and reads a direct-mail advertisement is more likely to purchase the product advertised than is a person who reads an advertisement for a product in a magazine that they subscribe to. Although the primary intent of most direct-mail advertisers is to convince people to buy products from their homes, direct mail can also lead to increased sales in stores by customers who prefer to see a product prior to purchasing it.
Direct-mail advertising usually consists of advertisements for products to be purchased from the home, so the perception that it is bad for the environment is misguided. Because of direct-mail advertising, millions of people buy products by phone or online -- products whose purchase would otherwise require the use of a car, thus adding pollutants to the air.
Which one of the following, if true, would most strengthen the argument?