Amazon.com adds web services to its offerings

Critics thought it was over the top when Amazon.com Inc. expanded from books into music in 1998. When the Web retailer let competitors start selling things alongside its own inventory in 2000, they said Amazon had gone nuts.

In both cases, Amazon proved them wrong. Media sales now total in the billions each quarter, and third-party merchandise, more profitable for Amazon than its own wares, makes up nearly a third of everything sold through the site.

Now, Amazon is making an even greater stretch -- selling storage, computing power and other behind-the-scenes data center services.