Two weeks ago I "gave birth" to another kind of offspring.
While finishing up a buying guide to phone systems and phones that ran nearly 400 pages and sells for $29.95, I realized that there are probably people who don't need everything in that book or don't want to spend that much money, or both.
I started chopping chapters, paragraphs, sentences and words, and now have an abridged version with 210 pages that will sell for $19.95 and should reach people who would not buy the bigger book.
I'm not afraid of hurting sales of the big book. I'll make decent money on both versions, and each book promotes the other one, as well as my other books.
There are many ways to re-package and re-sell the same words. Think of different sizes, electronic media, dramatic scripts, different languages, etc.