She gets to keep 70% of her book sales — and she sells around 100,000 copies per month. By comparison, it's usually thought that it takes a few tens of thousands of copies sold in the first week to be a New York Times bestselling writer.
The comparison isn't entirely fair, because Hocking sells her books for $3, and some $.99. But that's the point: by lowering the prices, she can make more on volume, especially impulse buys. Meanwhile e-books cost nothing to print, you don't have to worry about print volumes, shelf space, inventory, etc. And did we mention the writer keeps 70%?
There are definitely lessons that can be learned from this story, but I'm afraid the wrong people are going to learn the wrong lessons. Hocking is very social-media smart; her fans find her to be very accessible, and that makes all the difference, especially in the science-fiction community. And I think this can be considered some kind of proof that lowering prices on e-books could get publishers to sell a lot more books. But it doesn't mean that self-published authors are the future. Books need editors. Editors are a necessary part of the book-writing process. If the editors of the future are freed up from the enormous corporate publishing system, that might be a good thing. But this is not some sort of vindication for self-published authors, and it shouldn't be considered proof that your 5,000-page memoir is somehow suddenly readable.