Rudy Rucker was interviewed at selfpublishingreview.com. Rudy is one of my favorite writers. I discovered him when I started exploring cyberpunk, but Rudy is a different animal and his books are more like math-punk. His novel Wetware was the first thing that I read by him, and I still think it is his best.
Rudy has a blog where he is quite open about his job as an author. He describes himself as “mid-list”, which seems to mean that he sells books at a moderate rate, but is mostly ignored by the book industry.
In this article he discusses his adventures in POD publishing. He recently created and published a book of his paintings at LuLu.com. He has thousands of readers a day at his blog and you might consider this as having a built in audience for his work. To date he has sold 10 books.
His experience with eBooks is similar. He re-released some of his earlier books as eBook downloads, but sales over the past couple of years have totaled in the hundreds. This seems to be no way to make a living at writing this way.
He does not give figures for his fiction books as POD sales. I would guess that they are not really much better. I would also be interested to find out how his new books are selling through traditional publishing houses, just for a base of comparison.
He says that traditional publishing has little to offer him except for an advance. They do not promote his books other than to put a listing Locus, (which I doubt many people read). They send out some review copies. Other than that, the traditional book publishers take a big chunk of change for doing nothing more than listing the book in catalogs and shipping out the orders.
In the last few years some of the larger book distributors have gone out of business. You can only buy books at book stores or online today. In the past every department store had a good book department and every corner store had rack of paperbacks near the magazines. The book business is bad, and that means that authors will have to find new ways to reach the dwindling few people who still read for pleasure.