Design lives in a world of pitching, problem-solving, negotiating, exploring, researching, budgets, deadlines, and testing—a world of marketing very much embedded in the processes of business. But don't take a designer's word for it; look to business trends, where design is increasingly recognized as vital to business. For example, businesses who recognize the value of investing in design can compete for the Design Management Europe Award, now in its 4th year.
For designers who spend significant resources explaining to others how Design differs from Art, mentioning this award to a client might keep them from thinking that it's all just about "making things pretty."