I think you are very right about the customer support thing. That is the one reason why I spend hundreds of dollars a year at Amazon. From the customer perspective (the only I have) you feel like a god. They nailed that one on the head.

Example: My girlfriend sat on my Kindle and broke it. I called and said that it was broken. Without any questions they just offered to send me a new one for free! After something like that I will always go back to Amazon (and tell my friends about it)...