'Supported' books

From Q&A With Mark Sisson

MB: I'm impressed by the way the book and the website complement each other. 

MS: Almost all readers of the book wind up back at the website because it's a constant source of new ideas, philosophies, recipes and communal support. So everyone who goes to the site should eventually get the book and everyone who gets the book should eventually go to the site!

Conjecture: with the emerging ebook we will see a new definition of a "book," at least non-fiction books. It will become more like a piece of software — "supported" on an on-going basis via the author/publisher's web site. The book itself may even be constantly tweaked as the author incorporates new information and changes his/her own conclusions.