Most people believe authors make a lot of money from book sales.
While this is true of many best-selling authors, the bulk of the money most likely comes from other sources. J.K. Rowling makes a fortune from the Harry Potter tie-in products.
Many authors make money by becoming a paid speaker. They are an expert in their field and can earn a six-figure income from one speaking engagement alone!
To learn more about getting paid as a speaker, read Lilly Waters' book "1001 Ways to Make More Money as a Speaker, Consultant, or Trainer".