No it isn't, because it's markedly less efficient. Amazon is, literally, taking the concept of the "store" and putting it online - yes they've done that already, but the instant gratification of receiving your item same-day; that's a true shopping experience that you, previously, could only really have with Brick and Mortar shops.

Instead of physically shopping inside of a store where you will have fewer selection, you shop online with a lot more selection, a powerful search based interface, recommendations, reviews, etc...; then have the items efficiently sent to you same-day.

Amazon is very successfully grounding the "internet" in the real world - and they are eating quite a few lunches.