I use Amazon for my books all the time. Its nice because you set your price and just wait, but it sucks bc they seem to be taking a lot of money from you. I think they took like $12 on my last sale which was ~$110ish. They also have a weird payout period, where they only give you your money ever 2 weeks or something like that. Also, if you do sell from there, make sure you get a delivery confirmation. I had someone claim that I didn't send them their stuff. :-P