When I set up my CreateSpace account, I paid an extra $25 to make my book available to "extended distribution" channels. The way it works, your book is available directly from CreateSpace (Author gets about 45% royalties), Amazon (Author gets about 22% royalties), or Extended Distribution (Author gets 3% royalties).
So I selected Extended distribution. What that means is that bookstores can buy your book for a lower cost. I looked at amazon, and I found that 5 parasite bookstores were offering MY BOOK on Amazon cheaper than getting it directly from Amazon! Needless to say, I turned off that channel, as it is nothing more than a way to cheat authors out of royalties. I can't stand parasites. I put months of my life into my book! Now, the only way it is available is directly through Amazon or CreateSpace.
I did, however, leave the library extended channel open.