There are moments of extreme power in human exchanges, instances where influence can be wielded for the good of both parties. And one of these moments is when somebody says “thank you” to you.

But, you know, we often handle these opportunities poorly.

A client thanks you for your help, and you say, “No problem. We would have done it for anyone.”

A co-worker asks you for your assistance, and you say, “Sure, it was easy. Nothing to it.”

A supplier sends you a note of appreciation, and you leave it at that. Not only are these relationships not furthered by your action, or inaction, but we may have actually damaged them.

Making someone feel unappreciated, incompetent, or not worthy of a response is a sure-fire way not to increase your influence.

You know, another potential problem is when the exchange is framed such that the other party feels that they’ve just done a favor for Vito Corleone – you know, “Someday, I may call upon you to do a service for me.” Saying things like, “And now you owe me one” is a sure-fire way to build animosity and opposition.

Be prepared, and use powerful language. Robert Cialdini, author of the seminal work Influence: Science and Practice, suggests what you should say in this extreme moment of power. When someone says “thank you” to you, you can simply respond by saying, “My pleasure, because I know, if the situation were reversed, you would have done the same for me.”

And watch as the other person nods furiously in agreement. And you have now used language to expertly and subtly earn a chit, an informal influence credit.

Practice this until you can use this or other similar language that you feel comfortable with to create a compelling yet conversational exchange.