Online marketers often get inquiries from geographies they cannot serve. On the other hand, direct mail marketers can buy every address in their own zip code!

1to1 Media: Cinnabon Uses Direct Mail to Tempt Potential Customers, 2009-Jul-20

Hill and his team designed a program to send direct mail pieces to small businesses within a two-mile radius of certain Cinnabon mall locations. …"We mailed out 60,000 posters that companies could hang in their break rooms, each containing 20 perforated coupons."  … Money Mailers' numbers show that the campaign produced a 54 percent return on investment.