The Importance of Niceness
A classic secret of good customer service is simple: hire nice people.
Although we usually think about external customers when that observation is made, the benefits also accrue to internal customers. Consider how much time is consumed when employees fail to get along. Such failures lead to turf wars, productivity setbacks, complaints, resignations, litigation, and low morale. All of those can indirectly harm external customer service.
We don't hire people as much as we hire relationships. In most cases, the ability to maintain positive relationships is vital, no matter how brilliant the individual may be.