Watch for more book back-matter

DVD's provide their "making of" bonuses and funny outtakes, websites provide secret material that's unlocked by codes. Until recently, books just ended with "The End." Now publishing is catching on and catching up. The surge of Book Club questions and author interviews after the final sentence attests to it.

Edgar & Ellen books provided a hidden code that led readers to the site. 39 Clues will take you on a multimedia quest.

I predict that the popularity of our next series, Kaimira Code, will hinge largely on the mysterious back matter that provides coded messages, an unfinished manuscript and a lost diary.

Keep an eye out for a growing trend in intiguing, fragmentary content--the end after the end...