Okay, so there are a lot of differences. Too many to go into on this blog.
But, let me give you a fascinating example involving a particular book and its place on the bestseller lists.
Workman Publishing has recently released an incredibly cool book called Gallop by Rufus Butler Seder. When you flip the pages of the book, the pictures really seem to be moving. It's amazing. It's fascinating. When you see this book, you can't help but want to own it. Also, it has a simple and surprisingly good text. And a nice big, clear font. This is one of the few books that can equally fascinate both children and adults.
To get an idea of what I'm talking about, check out Workman's website. In the far right corner you'll see a horse galloping... this is what happens when you turn a page of the book. In the actual book, the action isn't quite that fluid, but it's pretty close.
The Booksense list of children's bestsellers currently lists Gallop as its number one bestseller... a position the book has held for two weeks. The Booksense list is representative of the sales of independent (non-chain) bookstores.
Now check out the listing for Gallop on the Amazon website. As of today, Gallop is ranked at #9,483. Pretty incredible, isn't it? How could a book be so popular in bookstores and not popular at all with an online retailer?
For one thing, look at the pictures on the Amazon listing. They don't convey the visual impact the book has. Also, there are only a few reviews (the book just came out last week, so not a lot of people have seen it so far). And the book is listed as not being available for 4 to 6 weeks. (Workman is a relatively small publisher and they're trying to fill the huge demand for the book.)
Why is Gallop so high on the Booksense list? Because independent bookstores are talking up the book, displaying it in prominent locations and showing their customers a book they think is intriguing and creative. And, in the end, it comes down to the fact that you need to actually see Gallop. You need to hold it in your hands. You need to be able to play with it. And, in the end, that's something that you can't do on Amazon.