Are pre publication books illegal to sell?

I was wondering if the pre publication books could be sold on eBay? Pre pub books are the books that authors and publishing companies send to libraries and bookstores for their employees to read before the book is released to the general public. They are basically a sample book that determine whether these book outlets will buy more copies of the book for their patrons to read. I have a lot of them in my collection that I am wanting to get rid of. On some of the books it says "Not for retail sale" but would eBay be considered that when I would be a private seller?