Abstract
Acquisition of feedback from customers has become a necessity. It can be divided into direct and indirect.
The indirect feedback is pursued via mystery shopping or via a secret or inspecting customer who observes feelings while drawing services or shopping for goods. He did not spend his own money, so the impression differs.
Since about 2005, D Telecom and Skoda Auto, direct feedback has been used. It was copied very early by other telecommunication companies and automobile factories, followed by e-shops.
We introduce development, risks and difficulties of these methods called Customer Satisfaction Index, used as CCS, CSI, ICCA etc., including misusing these tools in employees' assessment based on customers' opinions.