The Millionaire Next Door: A Complete Summary The Millionaire Next Door is a book about how to become rich written by Thomas J. Stanley and William D. Danko. In order to explain how to become rich, the authors use logical explanations based on research. According to a 20-year study of a group of 1,000 millionaires in the United States, the authors came to some fascinating conclusions. Although many Americans think that there are only a few ways to...