Some person I don't know sent me an IM, and it went like this...
xxx: Hi, I have been reading your book.
xxx: I think it's awesome...
popworldCP: thanks!
xxx: this book helped me fully grasp the concept of OOP
xxx: loving it!
popworldCP: awesome... that was really my mission, and i'm glad even one person "gets it" now.
xxx: it takes less coding to do something and it's easier to read
xxx: haha
xxx: i read well over 7 books on this subject
xxx: they never fully go into explaining the concept
xxx: your whole book is about OOP
xxx: thank you so much for a great book!
If the book never sells more than ten copies, that made it worth it.