Science fiction author John Scalzi does great analyses of his book sales patterns. All authors can benefit by seeing these kinds of figures and discussions. Scalzi describes himself as a “four-quadrant” author: “my income as a novelist comes out of four areas: print, eBook, audio, and foreign sales”, which leads to “a writing career is not at all unlike a stock portfolio — diversify for long-term success.”
To him, the major benefit of using a publishing company instead of self-pubbing is the ability to fully exploit all those formats. Yes, anyone can do ebook and print–but please take the considerable time and effort to do it right. You can self-pub in audio, although it takes a lot more work and time. Unless you are a big-name author, or have the assistance of an agent, few self-pubbers make much headway in selling foreign rights to their books.
He did a study of the sales of his most recent release, Lock In, which I found very interesting to read (the analysis, not the book, which I haven’t read).
(And he’s apparently obsessed with psychiatrist/physician/scientist Wilhelm Reich.)
John Scalzi, covered in frosting, August 2012. Photo by Kyle Cassidy