Learn how changes in income impact satisfaction and understand the principles behind the marginal utility of income in modern economies.

Sean Ross is a strategic adviser at 1031x.com, Investopedia contributor, and the founder and manager of Free Lances Ltd. Ariel Courage is an experienced editor, researcher, and former fact-checker.

The law of marginal utility states that customer satisfaction decreases with each unit purchased. So, the more your customers purchase, the less satisfaction they get from each additional purchase. If ...