I've been hearing other terms such as 'passive' or 'active' related to Customer Satisfaction. Also to be remembered is that you must address all customers - Internal and External, so we're not just talking 'end user' anymore.
The measureables your company uses should be a mix of 'passive' and 'active' methods for determining customer satisfaction. Examples: Market Share; Customer Retention; Acquisition of new customers; Satisfaction; Profitability; and Customer Feedback,
From "Measurements of Customer Dissatisfaction" from Kaplan, R.S. and Norton, D. P. 'The Balanced Scorecard':
Many customers do not go to the trouble of complaining. They simply take their business to one of your competitors. Customer dissatisfaction indicators include complaints, claims, refunds, recalls, returns, repeat services, litigation, replacements, downgrades, repairs, warranty work, warranty costs, miss-shipments, and incomplete orders.
There are numerous sources of information concerning customer satisfaction - direct complaints and comments, questionnaires and surveys, reports from consumer organizations, reports from the media and sector studies.
One of the easiest ways to ask customers for help and one the usually turns up very valuable information is the focus group interview. Any capable facilitator who understands the objective of the research can usually do a good job. The real trick is thinking through the findings, interpreting what the group participants have told you and relating it to the quality of your product or service.