Walmart carries a very narrow range of goods, and leaves tremendous room for local businesses to still exist. Amazon will compete with everything at any time.

Walmart doesn't carry criterion releases or foreign films, and there is potential for local art movie stores or houses to exist to fill the need. Amazon carries movies at a much lower price than a local business ever could, and streams them too, again at lower prices than a theater. They try an get their fingers into everything, even service-based businesses, while walmart just does low prices on a selection of goods.