It's easier for the industry if every book is either a standalone one-shot, OR a staff-serialized-moneymaker like the Magic Treehouse or DK Eyewitness books. They don't deal with individual authors that way, they deal with the agent or the series publisher/editor.

And really, if a recent poll says 28% of Americans haven't read a single book, fiction or nonfiction, in the last year, I want to know where I can move to improve the quality of my neighbors. C'mon, guys, I'm in a /SLUMP/ of epic proportions, and still read three real, phyiscal books this week along with my writing, other people's electronic publications, and more!