In "The Copywriter's Handbook," Robert W. Bly emphasizes the importance of substance over style in copywriting. Instead of focusing solely on creating visually appealing text, a copywriter must thoroughly investigate a product or service to understand the motivations behind consumer purchases. This groundwork enables the writer to craft compelling arguments that resonate with potential buyers.

Bly argues that effective copywriting should not only be read but also understood and acted upon. The copy needs to present its arguments so persuasively that it compels customers to buy the product with a sense of urgency. Thus, the primary goal of a copywriter is to create content that leads to action, effectively driving sales by addressing consumer needs and desires.