Customer satisfaction (often abbreviated as CSAT, more correctly CSat) is a term frequently used in marketing. It is a measure of how products and services supplied by a company meet or surpass customer expectation. Customer satisfaction is defined as "the number of customers, or percentage of total customers, whose reported experience with a firm, its products, or its services (ratings) exceeds specified satisfaction goals."
The Marketing Accountability Standards Board (MASB) endorses the definitions, purposes, and constructs of classes of measures that appear in Marketing Metrics as part of its ongoing Common Language in Marketing Project. In a survey of nearly 200 senior marketing managers, 71 percent responded that they found a customer satisfaction metric very useful in managing and monitoring their businesses.
It is seen as a key performance indicator within business and is often part of a Balanced Scorecard. In a competitive marketplace where businesses compete for customers, customer satisfaction is seen as a key differentiator and increasingly has become a key element of business strategy.
"Within organizations, customer satisfaction ratings can have powerful effects. They focus employees on the importance of fulfilling customers'' expectations. Furthermore, when these ratings dip, they warn of problems that can affect sales and profitability.... These metrics quantify an important dynamic. When a brand has loyal customers, it gains positive word-of-mouth marketing, which is both free and highly effective."
Firms need reliable and representative measures of satisfaction to effectively manage customer satisfaction.
"In researching satisfaction, firms generally ask customers whether their product or service has met or exceeded expectations. Thus, expectations are a key factor behind satisfaction. When customers have high expectations and the reality falls short, they will be disappointed and will likely rate their experience as less than satisfying. For this reason, a luxury resort, for example, might receive a lower satisfaction rating than a budget motel—even though its facilities and service would be deemed superior in ''absolute'' terms."
The importance of customer satisfaction diminishes when a firm has increased bargaining power. For example, cell phone plan providers, such as AT&T and Verizon, participate in an industry that is an oligopoly, where only a few suppliers of a certain product or service exist. As such, many cell phone plan contracts have a lot of fine print with provisions that they would never get away if there were, say, 100 cell phone plan providers, because customer satisfaction would be far too low, and customers would easily have the option of leaving for a better contract offer
"Customer satisfaction provides a leading indicator of consumer purchase intentions and loyalty."  "Customer satisfaction data are among the most frequently collected indicators of market perceptions. Their principal use is twofold:"