The first keynote at the Web 2.0 Expo 2007 was a second helping of Jeff Bezos, who said much the same thing he said at the Web 2.0 Summit last November: Amazon wants to sell you pay-as-you-go computing infrastructure.

Bezos didn't trot out the term "muck" as he had in the past, perhaps wary of offending those wading knee-deep in IT. But he did pitch Amazon's pay-by-the-drink infrastructure as a way for companies to manage the heavy lifting, the basic IT services that are the "price of admission" for Web-scale businesses today.

The on-demand services Amazon offers include E-Commerce Service, Simple Que Service, Simple Storage Service (S3), Elastic Compute Cloud, Mechanical Turk, and Alexa Web Services.

If Bezo's message -- buy your infrastructure by the sip and the byte from Amazon -- hadn't changed appreciably, demand for Amazon Web Services had. Bezos reported that Amazon's S3 had reached 5 billion objects, up from 800 million in July.

As far as metrics go, that's a hard one to judge: huge numbers of files, while impressive for sheer size, don't translate easily into customers. A fivefold increase in nine months could be just a few dozen guys with a lot of photos, or something like that.

Asked by conference founder Tim O'Reilly (at right in photo) whether Amazon was making any money on this, Bezos answered, "We certainly intend to make money on this," before finally admitting that AWS wasn't profitable today.

At least Bezo's figures point to an obvious increase in demand for on-demand IT.

Bezos described how the service proved useful for his space startup, Blue Origin. Back in January, Blue Origin posted video of a trial flight. That prompted links from Slashdot.org and BoingBoing.net, both of which can send huge amounts of traffic to a Web site.

Large traffic spikes typically will crash a Web server or lead to hosting problems if not anticipated. But Bezos explained that because Blue Origin had served the videos from S3, the sudden 758-Gbyte data spike that occurred as a result of the links didn't cause any problems and resulted in a bill of only $304.23 that month.

Just before Bezo's arrival on stage, O'Reilly observed that as the Web develops "we're becoming part of a great machine." If that's true, Amazon and its Web services will surely be there to feed us on-demand.