Piers Anthony? That guys had to have sold like a bazillion books. And it is too bad a figure can't be had for Koontz. I understand the rationale but that guy is a writing machine, just from the number of books he has written he must be top 10 at least. I think I remember reading on a book jack like ten years ago or so the publisher saying he had sold over 200 million books. So, what is he now with his Odd Thomas series and the other stuff from the last decade?

What will be interesting is to see how much the emerging market for audio books will change figures. I have devoured about 40 or 50 audio books this year and I have friends who are now getting into them as well. One guy has been listening to the WOT series from start to finish, he has listened to Sanderson's first book in the new series and he listened last year to the whole Martin Song of Ice and Fire series.

Just in this sci-fi/fantasy/horror grouping I have listened to (this year):

1 Stephen King book
2 Clive Barker books
3 Joe Hill books (and will listen to his new novel before year's end)
3 Steven Erikson books
5 R. Scott Bakker books
1 Brandon Sanderson book
1 Brandon Sanderson/Robert Jordan book
1 Guy Gavriel Kay book
1 Sci-Fi collabrative work (Metatropolis)
1 Edgar Allen Poe collection of 14 short stories
A 6 disc series of H.P. Lovecraft stories
1 Peter Clines novel

So, 20 complete books and however you want to count the Lovecraft stuff. Throw in conservatively another 4 or 5 before year's end. And even though it isn't relative to these genres, just for info's sake, I will have probably completed about another 20 or 30 non-fiction audiobooks by year's end.

And from what I read, the market is growing in leaps and bounds. Wonder how big audiobook sales will be in the next 5 to 10 years.