School of Business: Most educator may teach business yet they know nothing about real business school. Let me share with you what Rich Dad and Donald Trump say about the best business to start. By using this formula John G started in 1980 in 2000 he was still earning income from the business he started in 1980. With one business he was earning $75,000 per week. He owned 181 companies at the time and earn a total of $30,000,000 in May of 2000 by using this formula.