I wouldn't be surprised if customers start to discover alternatives, like Walmart's "site to store" feature.
Honestly, I don't see this happening at all. If you have even the most minor issue after receiving a purchase, Amazon will spare no expense to ensure your satisfaction. I've never had an experience with Walmart that even begins to compare to those I've had with Amazon. For example: I bought a Kindle from Amazon 4 years ago, and a few months back I accidentally cracked its casing. After calling up to see if they would offer a discount for a replacement, I was delighted when the rep told me that they would replace it -- sans return -- at no cost to me. Just imagine trying to return a 4 year old purchase to Walmart. You'd be laughed all the way home.
Yes, but customer satisfaction didn't get Walmart where they are today. It's all about those low, low prices. I'm glad customer service treated you so well. Luckily, the Kindle is a product manufactured by Amazon, one designed to help you buy more things from Amazon. I doubt you'd have gotten the same treatment trying to replace a broken Xbox 360 or iPad.
Funny thing about that, I've scratched plenty of PS3 game discs bought there, and have never had an issue getting them replaced at no cost. All I had to do was send the discs back within a month of receiving the replacements. Additionally, Amazon is steadily climbing up to Walmart's level (some might argue it's there already) and it IS taking customer satisfaction seriously. And if you're old enough to remember Walmart before Sam Walton died and his bastard kids took over, then it should be pretty clear that Walmart got big because it was so consumer-centric, much like Amazon is today. It didn't start down the path of the evil leviathan corporation until Walton was six feet under and his offspring grabbed hold of the reigns.