The full list is as follows:
1. James Patterson, $70 million
2. Stephenie Meyer, $40 million
3. Stephen King, $34 million
4. Danielle Steel, $32 million
5. Ken Follett, $20 million
6. Dean Koontz, $18 million
7. Janet Evanovich, $16 million
8. John Grisham, $15 million
9. Nicholas Sparks, $14 million
10. JK Rowling, $10 million
Franzen affair, it does show that "serious" writers, the literary writers are not the ones making the money. The ones making money are the "commercial" writers. In the Forbes list, there are representatives from multiple commercial genres: thrillers, horror, romance, fantasy. No sci-fi though. Of course, no westerns because the western genre is dead. Which shows you that if you want to make money: write novel featuring a vampire lawyer falling in love with a teen girl, who during a field trip to the Supreme Court, must be saved from a bomb made by zombie terrorists who vow only to blow it up if the case in question does not turn out the way they like it to.
Blockbuster! It will be the release of the century!
Seriously, though, the list shows what Americans are reading. It could be taken in multiple ways. We take it as a sign that Americans overall have bad taste in reading--I mean, James Patterson! But it could also mean that at least Americans are spending millions of dollars on books, and that we are all reading a lot. It could also mean, as Lev Grossman pointed out, that the serious, literary writer is endangered of being extinct (but have you looked at MFA programs?).
Bestsellers: A Very Short Introduction. For those worried about the great American literary culture, it's there, and if it's good enough, it will last longer than all of us. Bestselling fiction that has any literary worth will also be there along side the great literary work. I believe, for example, Stephen King will easily be a classic of American literature, as well as a lot of genre fiction. Writers, most writers I believe, really like what they're doing--literary or not--money is nice, but it isn't why you're in this in first place (even though it's rather hard to believe when James Patterson used to be marketing executive and Nicholas Sparks has delusions of graduer)...Karma works out at the end.