What if we were talking about Walmart instead of Amazon, and shoes instead of books? There are many brands and styles of shoes that Walmart doesn't carry becaus

What if we were talking about Walmart instead of Amazon, and shoes instead of books? There are many brands and styles of shoes that Walmart doesn't carry because they can't get a low enough price to make it worthwhile. Of the brands and styles of shoes that Walmart does choose carry, some they may promote by placing them on an end cap, and others can be hard to find, or even stuck in the stockroom and not displayed for customers. Nobody thinks Walmart is being unfair. Walmart can choose what merchandise to carry and how to display it. So what's different with Amazon? Is it their infinite shelf space? Is their industry dominance and market power?