Amazon Cloud Computing Had Nothing to Do With Selling Excess Capacity

There's an urban myth that Amazon.com started Amazon Web Services, the cloud computing business, because it had already built the platform to support its own internal needs, and had extra capacity that it decided to sell.

But Amazon.com CTO Werner Vogels says the story is untrue.

"The excess capacity story is a myth," he says. "It was never a matter of selling excess capacity, actually within two months after launch AWS would have already burned through the excess Amazon.com capacity."

Rather, Amazon Web Services always was seen as a business with excellent growth prospects.

How and why did Amazon get into the cloud computing business? - Quora