Another aspect of the massive fail at Amazon

I am still not happy with Amazon's response to their massive fail, but I don't want to get into the whats and the hows and the whys - other people are doing a much better job of that. I have a question about alternatives, though. There have been many suggestions on alternatives on where to buy books (I'd like to suggest indiebound.org), but what about alternatives on where to sell books? Amazon Marketplace has become another kind of convenience that's not so easily replaced. Are there discussions about this someplace I haven't come across yet?