Increasingly, big firms are launching into "the cloud" to sell services, while small firms plug in, waving goodbye to the server hidden in the closet.
"The future is about having a platform in the cloud," Microsoft Chief Steve Ballmer said of the trend in a July e-mail to employees. The company has invested heavily in new products that will be announced in upcoming months.
About four years ago, Seattle-based Amazon.com Inc. began hatching a way to sell access to its complex computer systems. The company had already built up a robust infrastructure to support the world's largest online retail operation -- so why not let other businesses tap in?
Amazon launched its Web Services in 2006, and more than 400,000 developers have signed on to pay for services such as storage space, database access and computing power.
"Over the next decade you are going to see an incredible transformation, in my opinion," Amazon Chief Executive Jeff Bezos told shareholders earlier this year. "It doesn't really make sense for most companies to have their own data centers, just as it doesn't make sense for most companies to produce their own electric power."
Examples of businesses that rely on Amazon are Twitter and even The New York Times, which uses Amazon to partly host its "TimesMachine," the newspaper's archives, including full-page image scans of papers going back to the 1800s.
Amazon's price for Web services starts in the pennies -- to use its Elastic Compute Cloud, for instance, Amazon charges 10 cents per hour per server.
"We routinely send people monthly bills for 17 cents," Bezos said. "If you store a gigabyte of data for a month, we'll send you a bill for 15 cents."