The Economist goes to a lot of effort to describe something that is not particularly relevant to getting a sense of the scale of AWS - these are "virtual" instances, which may be spun up and removed fairly rapidly. All we really get is a sense of the transactional volume of instance creation. This is further confused by the roll out of new EC2 products - it's well within the realm of possibility for an individual to roll out 1000 Micro EC2 AMI instances in a single day when experimenting.<p>In particular, The Economist fails to justify the statement "The results suggest that Amazon’s cloud is a bigger business than previously thought."<p>More interesting to me, would be the number of _physical_ servers, and their characteristics, in the Data Centers. Or, probably as useful, is the number of "Instance-Hours" along with the scale of those instances.<p>The most interesting part of the article, for me, was my first (that I can recall - Google Trends shows it's been around for two years) exposure to the phrase IaaS (Infrastructure as a Service). I guess it makes sense that if we commonly use SaaS (Software...), and, in the last year, PaaS (Platform...), that we should bring it back full circle.<p>I do take exception, BTW, with the phrase "The most interesting layer—the only one that really deserves to be called “cloud computing”, say purists—is “infrastructure as a service”". I was present at the birth of Loudcloud in September of 1999, one of the first (alas for my Stock Options, failed) attempts at a "Cloud Platform" - and I assure you that we had no intention, at the time, of providing the 'infrastructure' as a service. It was all about the Databases and Applications servers.
Summary for 2010: all SaaS has sales of $11.7 billion; PaaS (I think they mean services like SalesForce, AppEngine, and Azure where you write your apps on their service) $311 million; Amazon $500 million.<p>Add it all together and you have roughly the size of the remaining U.S. steel industry which is rapidly giving ground to China. My point being the cloud is going to be a sorry economic substitute for dismantling the U.S. manufacturing base.
Original source for most of this is at<p><a href="http://www.jackofallclouds.com/2010/12/recounting-ec2/" rel="nofollow">http://www.jackofallclouds.com/2010/12/recounting-ec2/</a>