The two key things that make a successful long-term relationship and help in customer service.

The Gottman Institute have researched relationships for the past thirty-five years. They see two different kinds of couples in their results.
There are “masters” and “disasters”.  The “masters” of the art of relationships maintain stability, harmony and longevity. “Disaster” couples are highly emotional in the way they respond to the stresses and demands of life. Their responses foster unhappiness, contempt, and the eventual deterioration of the relationship.Being kind and generous to partners and customers; customer service

Conflict is an inevitable part of life. How couples deal with conflict makes all the difference if the relationship will thrive and survive. Those who react with the more primitive “fight or flight” response to stress have more problems in their relationship. Those couples who manage to stay calm and rational when under stress have better relationships.

The two traits that “masters” of successful relationships have are:
Generosity and Kindness.
Those who act with generosity and kindness grow in their love for one another and have a more satisfying relationship. The secret to forming a lasting partnership is be kind and generous. In practice this means being understanding and forgiving.
These qualities are also useful for dealing with difficult people at work. You can learn to be kind and generous towards difficult people, grumpy customers and challenging colleagues.