Any company that has been around for more than six or seven years has had to deal with changes in the technology stack. Naturally this has serious implications to the clerical staff: those that actually deal directly with the customers. Of course most successful companies hire employees who are quick to learn anyhow. Yet when you have major system wide changes, it is of tremendous help to have a couple folks on board who are both astute at learning on their own as well as at communicating to and teaching the new technology to others.
It takes a certain type of personality to be comfortable with teaching coworkers: this is not like an elementary school teacher nor even a college professor. To be effective the instructor needs to be comfortable enough in their own learning abilities to stay "ahead of the curve" and hence secure in their position.
They need to possess patience for those who are slower to grasp new concepts, and yet appreciate the effort their fellow employees are making, and have a means to be continually encouraging. Companies that have found the keys to long term survival have also found how to keep their internal "teachers" engaged and on board.