Great topic, Daithi. Here's some more fuel for the fire.
Here's two posts about how much Lynn Viehl, an author with a book on the New York Times mass market bestseller list, has made off her bestseller,
Twilight Fall.
http://www.genreality.net/the-realit...mes-bestseller
http://www.genreality.net/more-on-th...mes-bestseller
Long story short, her net profit after a year was about $25,000, with 89,142 total sales. And the publisher’s portion of sales on the book was around $453,840. She estimates about $250k net.
And it's not like this was her first novel or anything. It's the sixth in the series, and debuted on the Times mass market list at #19.