I don't really see what the point of this article was - the entire message is summed up in one phrase "Amazon has mastered ... making money in low-margin businesses."

There is really no additional analysis, explanation, or extrapolation beyond that statement. The key thing that inspired this was that Amazon "introduced spot pricing for servers" which is never actually explained for anyone that might not know what that even means.

I think there was a seed of a good article here, but it should really be more than just stating an idea and leaving everything else up to the reader to determine.

Added a bit of explanation of spot pricing, per your request.

Yes, that's why I use their (slightly overpriced) services.

It couldn't possibly be the features, reliability, ease of us, awesome documentation and almost instant availability.

You are paying for all those things. If they are better at all of those than the competition, I'm not sure if they are overpriced.

To demonstrate that spot pricing is a CORE competency you would need to show that it is applied ACROSS their businesses. Where's the evidence they use it much in books sales, music etc?

"Of course their technical and operational execution is excellent"

Clearly spoken by someone who has only seen the beast from the outside...

As a customer of s3 looking to use ec2, can you elaborate?

ec2 is one part of amazon that I haven't any direct experience with, but anyone who thinks that amazon is a good technology company should spend some time chatting with the legion of ex-amazon employees out there.