To reach the best-selling state of the times, not only needs to sell at least 5000-10000 copies a week, but these sales also need to be diversified sales. You can take an example from Britain book writing. This means that you can’t sell 10,000 books to an existing follower list through your personal website, nor can you sell thousands of books from single markets such as Barnes and Noble. With Kindle Direct Publishing (KDP), you can publish books on Amazon at your own expense and make money in just 24 hours. ... Vanity Press by Amazon KDP is completely and 100% free. On the authority of book writer team, the "average" Vanity Publishing House sold approximately 250 digital books in its lifetime. In comparison, the average sales volume of traditionally published books is 3,000 copies, but as mentioned earlier, only about 250-300 copies were sold in the first year. Many authors and agents know that the average first-time author's income in a new book is about $10,000. After paying agency fees and investing in promotions, there is not much left.