I have a large library of book.. get more every day.
Once in a while, I look over the collection and am convinced that the best use for most of the book would be to give them away. Not all of them.. but even some of the ones I love best would help the world more if I found someone that wanted to read and gifted it.
I can always buy or print more.
What About a Service To Help Me Give Away Books?

BookMooch is a community for exchanging used books.
BookMooch lets you give away books you no longer need in exchange for books you really want.
Learn more at the BookMooch web site
There's another site called readitswapit.com which helps people to swap their books, but it does require both people to swap to read one of each other's books. The Bookmooch model gets around that requirement nicely by using credits instead.
there's quite a few of these out there. Plenty of books for anyone that needs something to read.
Thinking about this,.. reminds me that the primary purpose for most books today is NOT to get information out.. these communities are there for the experience, and likely would be an interesting group of include in a book marketing promotion.