Customers often have underlying emotional needs that need to be met for them to feel they've received extraordinary service. For example, a customer may describe a problem they've had with your product or service. A good customer service rep will try to fix the problem. An outstanding customer service rep will understand the customer also has the emotional need to be acknowledged for the time they've wasted and the disappointment of experiencing the problem.
The next time you serve a customer, particularly someone who is experiencing a problem, see if you can uncover an emotional need. Be careful -- customers rarely tell you about these needs directly. You'll need to use a strong sense of empathy to discover them!