At best, it was always a guessing game about how many books self-published or indie authors sold and how much money has been earned. For authors who would like to make a living as writers and are considering self-publishing, this is a huge issue.
Below are a pair of links that you need to visit if this topic is important to you. Both are essential reading. Rather than talk about what each has to say, I encourage you to leave this site and visit the two sites linked to. Here they are:
I promise you, this will be time well spent.