I'm Stuck on an Island and can Never have Too many of the Best Marketing books.

Like Ankesh said, you can and should Never stop Learning from Fresh New ideas & concepts!

And if you Happen to need a Marketing book on How to Market your Books...

John Kremer, 1001 Ways to Market Your Books & John Kremer's Book Marketing Tip of the Week...

And other Good Stuff...

http://www.bookmarket.com/

Phil