These days, you cannot limit yourself to just one area of expertise in business and professional life in general. Competition is too fierce. Anyone can start a business if they have a laptop. Therefore one must continue to differentiate without losing core competencies in the process. One thing that keeps the best business people at the top of their game is a continual thirst for knowledge. The more information you have access to and can readily incorporate opens the playing field wider. Those who get stuck in a rut are typically those who stop learning and improving themselves. Don't just rest on the victories of yesterday, or even today because they will soon pass and make you obsolete. Garner new skills and learn how to better execute the ones you are already good at.