The most frequently used medium for direct marketing is direct mail, an advertising discipline in which marketing communications such as real estate post cards, sales brochures and business booklets and mortgage door hangers are sent right to customers using the postal service.
In developed countries like the US and UK, bulk rates allow marketers to send direct mail at lower rates than first-class mail, rendering direct mail a significant percentage of total postal volume. To qualify for third-class rates, direct mail marketers must use specific direct mail layouts and employ a direct mail house to sort in particular ways (reducing direct mail costs for handling).
Direct mail enables the marketer to use various direct mail designs and direct mail pieces. In fact, an entire stratum within the direct mail industry deals with direct mail materials such as brochure paper and post card templates for direct mail printing.