For the poor students trying to save a buck on textbooks. I hate how much textbooks cost and then if they let you sell it back you are lucky to get 1/16 of what it cost you even used. For me rental has been great, it is much cheaper and I get rid of the books after. I don't care if you use the codes on here but if you are sick of the normal textbook routine I would check out the sites. Also a great site to find the cheapest prices on textbooks (rental/used/new) is Cheapest Textbooks
enter the title/author/keyword/ISBN and it will search Amazon, B&N, Half.com, Chegg, etc and give you the prices in a one stop search. I could care less about getting any referrals on this, I didn't even sign up for that reason I did so I got easy ways to pass on other options to people that are sick of spending so much on books. I carry these on me and when people ask about cheap books for the class I let them know or if I got it cheaper at Half.com/Amazon whatever I let them know that instead.