Direct marketing stands out as a uniquely accountable type of advertising, allowing businesses to measure their effectiveness directly. This method enables marketers to track responses and conversions, providing clear data on the return on investment. Unlike other advertising forms that often rely on broad metrics, direct marketing offers tangible results, making it easier for businesses to understand their impact and adjust strategies accordingly.

In "The Copywriter's Handbook," Robert W. Bly emphasizes the importance of direct marketing as a tool for accountability in advertising. Since it allows for targeted communication directly with consumers, it fosters a relationship where responses can be precisely measured. This creates a feedback loop that helps marketers refine their messages and improve their overall campaigns, leading to greater success in reaching their goals.