For the real, genuine lowdown on what is happening in publishing, who is earning what and how, read Hugh Howey's report here. Those of us who self-publish and keep up with information on the web have suspected some of this, but to see the figures and charts is just staggering. They are from Amazon US.
You need to read this, now. Here's just one of the fascinating charts:
Don't hang around here! Off you go!