According to this article about a spammer who sells enlargement pills, you'd be surprised.
Among the people who responded in July to Amazing's spam, which bore the subject line, "Make your penis HUGE," was the manager of a $6 billion mutual fund, who ordered two bottles of Pinacle to be shipped to his Park Avenue office in New York City. A restaurateur in Boulder, Colorado, requested four bottles. The president of a California firm that sells airplane parts and is active in the local Rotary Club gave out his American Express card number to pay for six bottles, or $300 worth, of Pinacle. The coach of an elementary school lacrosse club in Pennsylvania ordered four bottles of the pills.
Other customers included the head of a credit-repair firm, a chiropractor, a veterinarian, a landscaper and several people from the military. Numerous women also were evidently among Amazing Internet's customers.
All were evidently undaunted by the fact that Amazing's order site contained no phone number, mailing address or e-mail address for contacting the company. Nor were they seemingly concerned that their order data, including their credit card info, addresses and phone numbers, were transmitted to the site without the encryption used by most legitimate online stores.
People should be smarter than this. If everyone would just quit responding to spam, sooner or later it would stop.