Alfons - About a year ago my comapny was working with a real estate development firm who was considering moving into the colocation business. We struggled to answer some of these same questions, to gauge if their business plan was viable. We were able to gather some information from Gartner, Tier 1 and a couple sources, but there in no single source for all of this information that I am aware of. Part of the problem is how do you define a data center? Anything over 1000 sf/sm? Does this include all corporate, and govermental data centers? These were some of the problems that we ran into while attempting to do market research for them.