Customer service is a large part of retaining your current revenue streams. While it would seem that it isn't a lot, much can be said for how people view your staff and how you might be willing to help customers feel satisfied with their purchase. Something as simple as a smile can make all the difference in whether or not someone purchases your products/services again and again.
Consider that the interaction with the customer sets the "face" of the organization. When that interaction is positive they will naturally feel that the staff is helpful. These personal interactions put the customer in a better mood which becomes part of their impression of the company.
There is also a mental spill over effect that occurs. A negative interaction by one grouchy employees will reflect on the entire business. In the opposite, a positive interaction will embed the memory and feeling together anytime someone thinks of the company.
Thoughts and feelings are associated. When we remember a company our feelings are often more important than the actual thought. As soon as we think about a particular company we also think of our feelings associated with it. These can be any flavor and variety.
For example, long waiting lines to talk to a customer service representative says one thing..."I don't care about you". It tells customers that you took their money but won't necessarily answer their questions or fulfill the implied contract when there is an issue. You just wanted their money and that is bad for long term business.
A smile is something important when we consider it within the context of the entire interaction. Helping customer service representatives understand why it is so important to have a positive and upbeat interaction with customers can make a big difference between a one time sale and life long customer. Something as simple as a smile can generate a long-term revenue stream.