I strongly believe that the most effective kind of power is not just one power but both reward and expert power together make a great combination to a healthy source of power. You need both powers to stay focused. The main reason for saying this is because it is observed that reward type of power are generally used by a person who want to get his or her work done by rewarding the appropriate reward if the desired targets are achieved and this will as a whole motivate the person to achieve his or her goals. I use expert power to train new individuals and to refresh current ones. I strongly think and believe that having expert power helps to gain the trust of others around you in helping them see that their leader can share their expertise. In many jobs and or lessons in life it takes an individual that is willing to share their expert power to train and teach their employees appropriately to succeed as a whole and grow together into something great.
Once you have shared your expertise with your team they will then pass that same method on amongst the company to help maker an even stronger and better team. In life even though some may not outright ask for it; the method of reward can be both great for the person receiving it and giving it. For the person receiving it gives them more of a drive to keep on going to achieve more and more, and for the person giving that reward they are helping keep their employees happy and working harder towards achieving higher goals that help his or her company grow even more. It is easier to grow with people that believe in you and ones that know you care for them as much as you do for your company because at the end of the day your employees are your team and your company.