Benson, thanks for your comment. Like you I tried a bunch of back-of-the-envelope calculations to see whether I could arrive at $45/mo. I concluded that all I was doing was hypothesizing more and more stuff. The McKinsey folks really need to be more detailed with their numbers if they want to be taken seriously. And yes, it's funny to see how they completely missed the big picture. I actually do believe that cloud computing will increase the computing budget of many companies, large and small. The reason is that suddenly compute resources become affordable and attractive to solve more business problems. Throwing some more machines or disks at the problem is cheaper than the alternative and suddenly becomes possible, even easy. So do it and save overall!