David Mattson is CEO and a partner at Sandler Systems, Inc., an international training and consulting organization, where he continues to be a trainer and business consultant for management, sales, interpersonal communication, corporate team building, and strategic planning worldwide. He is also the author of The Sandler Rules: 49 Timeless Selling Principles and How to Apply Them and coauthor of Five Minutes with VITO: Making the Most of Your Selling Time with the Very Important Top Officer.