Free Books! ($3.99 shipping)
Before I built my library here (using Ben Gunnink’s Now Reading Reloaded), I got familiar with GoodReads.com. It’s a good place to find recommendations for new books and keep up with what your bibliophilic friends are reading. It’s also a good place for cheap books.
There are plenty of online book swaps, but they all differ from the one at GoodReads in a significant way. The costs at Paperback Swap, SwapTree, and Book Mooch all come from the supply side: when you send a book to someone, you pay shipping. In exchange you get points, and someone else sends a book to you. The problem is that I’m a leech on the system. Books that enter my domain rarely leave, and I just want to acquire new ones. In these models, that’s not really possible, because they require you to contribute in order to participate.
But I don’t want to contribute, and I don’t think there’s any moral problem with that. With GoodReads’ bookswap, there’s no logistical problem, either. The solution is to move the cost burden to the demand side. When you buy a book, you pay shipping, which means there’s no need for you to “put some skin in the game” before you can request a book. It’s perfect for system parasites like me, and there’s an incentive to start contributing (a free book for every ten shipped).
If you don’t want to get involved in a community of readers, you can check out Alibris. They offer a ton of 99¢ books, and several easily found “$1 dollar off any order” coupon codes. No, you don’t get a penny back.
Trade or buy, and enjoy!