2. Put the customer in control. The best kind of customer service happens when management enables employees to put the customer in control. This require two leaps of faith: first, that management trusts customers not take advantage of the situation; second, that management trust employees with this empowerment. If you can make these leaps, then the quality of your customer service will zoom; if not, there is nothing more frustrating than companies copping the attitude that something is “against company policy.”
Bona tempora volvantur--by Guy Kawasaki: The Art of Customer Service.
The whole post is good stuff, but I’ve found at Microsoft this one is key.