Just found a post on the Human Being Curious blog, called What is a Loyal Customer.

It defines a loyal customer as having the following characteristics:

• A loyal customer will buy what you’re currently selling, and whatever else you come up with.
• A loyal customer feels more like a partner than a transactional buyer.
• Loyal customers stick with you, even in a period of crisis.
• Loyal customers are immune to the pull of competition.
• A loyal customer has a switching cost.
• A loyal customer will go out of their way to passionately recommend you to others.

Worth reading the entry in its entirely for the details.

So the question is: What are you doing to make your customers loyal?