If you still debate if the “Cloud” is coming, or if it makes economic sense for you, you may look at the new whitepaper that Microsoft has published with its own results:
Our analysis uncovers economies of scale for cloud that are much greater than commonly thought. We believe that large clouds could one day deliver computing power at up to 80% lower cost than small clouds. This is due to the combined effects of three factors: supply-side economies of scale which allow large clouds to purchase and operate infrastructure cheaper; demand-side economies of scale which allow large clouds to run that infrastructure more efficiently by pooling users; and multi-tenancy which allows users to share an application, splitting the cost of managing that application.
interesting data, even if you could imagine some of them already, interesting analysis model and data sets