How much money do you make if you sell a million books?

Excuse me, could you elaborate on the specifics of this scenario? Are we talking about physical books, e-books, or a combination of both? Additionally, the earnings from selling a million books would depend heavily on factors such as the book's retail price, the author's royalty rate, and any expenses incurred during the publishing process. Without these details, it's difficult to give an accurate estimate. Could you provide more information so I can better understand the context and provide a more accurate response?