I think another reason for Amazon's success reminds me of the movie, Miracle on 34th St. Specifically it's one of the few online stores that recommends other stores if:
1) Amazon doesn't have the item in stock
2) the other store's price beats Amazon's price
(yes I know Amazon is more of an online mall now, but from the customer's perspective it's really cool)
Another super revolutionary thing that (I think) Amazon came out with first was how customers could rate the quality of the products Amazon sells. Before hindsight, most people thought this was going against Amazon's own self interest; when in the end all of these things together built strong consumer trust and loyalty (a lot of repeat shoppers)
I'm a huge fan of ending endless speculation. It drives me nuts when coworkers sit in meeting after meeting and speculate about how something might work. How bout just trying it out?
From the article: "If you have a question about what you should do code it up, let people use it, and see which alternative gives you the results you want."
