March 4th, 2013
This includes core infrastructure, storage and other related infrastructure. Amazon.com by far the leader in this space is estimated to have a revenue between $3.5 and $4B this year. Rackspace made a little over $1B in total revenue of which about $350 mi is estimated to be cloud revenue. There are other similar players like GoGrid, Saavis, Joyent etc. We can estimate this IaaS market to be about $5-6B in size. The long tail in this case is not statistically significant as there are a finite number of vendors.