Amazon.com doesn't break out revenue for its cloud-computing business, Amazon Web Services. But a pair of analysts are taking a stab at estimating Amazon's cloud sales. Brian Pitz and Brian Fitzgerald of UBS, in a research note released today, say Amazon Web Services (AWS) revenue will reach $500 million in 2010 and $750 million in 2011, going all the way up to $2.54 billion in 2014.