Is there one reason why you'd want to sell books on Amazon?  Is it because you want to make some extra, risk-free money, simply to get rid of books laying around your house or you're just feeling generous and want to give some money to Amazon?  Why did you choose Amazon anyway?  Did you know there are a few other sites that you can list your books on that are, in fact, cheaper to sell on than Amazon? Let's concentrate on the first reason you may want to sell books on Amazon; that being to make money.
  If this is the case, you've made a great decision!  Making money selling books on Amazon couldn't be easier.
  Books are everywhere and the books that can be profitably be sold on Amazon are prevalent.
  Go into any thrift store, auction house, library sale, etc and I guarantee that you will find at least one book to make some money off of on Amazon.
The second reason to sell books on Amazon would be to get rid of books around your house that you already own.
  This is also a great reason!  You may not be making a profit because you probably paid full price for these books at one time but you now don't read them anymore and just want to get a few bucks.
  Amazon is a great place to sell these books and depending on the popularity of the books, they may sell very fast!  You can't find a book selling site on the Internet that gets more traffic than Amazon and with this traffic comes tons of people of all walks of life looking for a book.
There may be another reason you sell books on Amazon because you simply are not aware of other book selling sites out there.
  Did you know there are times where you can sell books on other book selling market places for more money than what you could get for on Amazon?  Due to the sheer number of books listed on Amazon, this can drive down the price sometimes and you're better off listing on other book selling sites.
Finally, if you have more money than you know what to do with you just want to give Amazon some more money.
  I'm obviously being facetious when I say this because Amazon has been increasing in market share of the book selling market and the general merchandise market for an online retailer for awhile now.
  I think they are doing just fine without you giving them money unless you are a billionaire.
I hope that I gave you some ideas and made you think a little bit as to why you decided to sell books on Amazon.