The Greatest Salesman in World About the Author Og Mandino is the most widely read inspirational and self-help author in the world. Former president of Success Unlimited magazine, Mandino was the first recipient of the Napoleon Hill Gold Medal for literary achievement. Og Mandino was a member of the International Speakers Hall of Fame and honored with the Masters of Influence by the National Speakers Association. Og Mandino died in 1996, but his books continue to inspire countless thousands all over the world.