I've recently bought a computer system, taken my family to a theme park and flown on an airline that were all rated tops in their fields for service. They had won awards and were widely cited as leading examples of service quality in action.

I ended up being disappointed. Not that the service was bad - compared with others in their industries, they were clearly better. But I had expected much more.

For example, the computer sales representative had touted his company's No. 1 service ranking in a highly recognized survey. That was the key reason I bought the system. Yet my calls for installation, trouble-shooting and integration with other hardware and software weren't the hassle-free encounters I had expected.

The service people turned out to be fallible human beings who had some trouble answering the phone. They were better than most of the others I'd dealt with in the computer industry. But in an industry that pays scant attention to customer support, that's not saying much.

This is important to understanding what causes poor customer service. It is not always a question of performance; it can be about expectations, as well.

To attract new customers, many organizations promise great service, display their service or quality awards, or show survey data that put them at the top of their industry. But those higher expectations raise the bar. It becomes difficult to meet them, let alone exceed them.

Here are some ways to keep customer expectations within reach:

Be very careful with promises you make or imply in your advertising, brochures, marketing and public relations activities.

Make sure your salespeople, dispatchers, receptionists, order desk staff, designers, or anyone in your organization who has contact with customers are promising less than your organization can deliver.

Continually research and test your customers' expectations and the factors that most influence them.

Make it a personal and, ultimately, an organizational habit to promise a little and deliver a lot.

Train your sales force to go after only those market niches where expectations match your delivery capabilities. It should become corporate strategy that all sales dollars are not equal. Some customers come with expectations that you can't meet or that will prove very expensive.

Don't try to negotiate your customers' expectations downward. You will lose this opportunity to improve yourself; you also risk losing the customer to someone who can meet its expectations.

Low service-performing organizations set themselves up for failure by raising expectations to attract new customers. They over-promise and under-deliver. High-performing organizations know that one secret of success is to under-promise and overdeliver. That is how they build reputations for service and keep customers coming back.