JEFF BEZOS TALKS ON HOW AMAZON is going all Army of Davids:

It is, in short, open source business strategy. Amazon has spent years building up a technological and physical infrastructure to their business, and instead of keeping it proprietary, they are selling their unused capacity to others. The Web services I mentioned here are only a few of what the company is now offering (you can check out the rest at aws.amazon.com), but it seems either a very brave or very stupid way of doing business. Give the tools of the big guy to the little guy, and you may just empower the little company that will one day bring you down. But then again, (to abuse a metaphor) if you’re the one facilitating the rising tide, it’s probably not your boat that’s going to sink.

I think it’s a smart approach.