When looking at books on Amazon, how do you know how well each one is selling?

You go to Books and sort by Bestselling (which I think might be the default). You can also click on the Bestsellers tab that lists the top 100 books, as well as the New York Times Bestsellers list. You can also see under the Product Details of any book the “Amazon Bestsellers Rank” to know where a book is (for example, right now, Guaranteed to Fail is at #2,903).

You can look right at the listing for the book to see how well it is selling on Amazon, too.

Just look up the title of the book. I’ll be using The Help for my example. When you look at the bottom of Product Details you can see that this book is doing well:

Amazon Bestsellers Rank: #4 in Books (See Top 100 in Books)
#2 in Books > Literature & Fiction > Genre Fiction > Historical
#6 in Books > Literature & Fiction > Literary