A few years ago I discovered this great website called Paperback Swap.  I love to read but don't always want to keep all the books I read, and selling to half price books usually doesn't even bring in enough $$$ to actually buy another book.  So the solution Paperback Swap!!  This is how it works, you register on the site and then post the books that you are willing to mail at your expense to someone else who might want them. The shipping costs are usually between $2 and $3. Then after you posts the books hopefully someone will want them and request them and you will get an email and respond to it and mail the book, once the book is received the receiver goes on and marks as received and you get a book credit to go find a book you would like.  I have also just discovered that you can purchase book credits for $3.45, so that means if you choose to buy book credits you can get a book for $3.45 with no shipping charges!!!  I love this site so check it out and let me know what you think.  www.paperbackswap.com