Since 1986, David Mattson, CEO of Sandler Training, an international training and consulting organization headquartered in the United States, has been a trainer and business consultant in the areas of sales, sales management, business development, corporate team building, and strategic planning. David wrote the forward to the second edition of David Sandler's book, "You Can't Teach a Kid to Ride a Bike at a Seminar."

Mattson is also a Wall Street Journal and BusinessWeek bestselling author of “The Sandler Rules: 49 Timeless Selling Rules and How to Apply Them,” “Sandler Success Principles,” and co-author of “Five Minutes with VITO: How to Make the Most of Your Time with the Very Important Top Officer.”