This involves consumer psychology, which is a topic that psychologists are studying and what businessmen are seriously studying. Of course, business research uses this psychology to stimulate consumer desire. Psychologically, we will mistake the credit line for the consumption strength. The bank sent us a beautiful card and approved a credit line of 50 thousand, but it has nothing to do with us. However, our psychology will mistakenly regard the credit line as the consumption strength, so swiping a card is often more generous than paying cash.