Long term client relationships find their foundations in a proper arrangement. Here are a few examples...
The farmer's market: I want to eat local foods that taste great. The farmer's market wants to give me local foods that taste great.
Google: I want to find what I am looking for. Google wants me to find what I am looking for.
Apple: I want Apple to be cool. Apple wants to be cool.
The trick is to align your service provisions with the needs of your client.