[mckilljoy]

It seems pretty reasonable to me. If Msft makes $1 billion on 20% of the market, and Amzn makes $3.8 billion (high-end analyst estimate) with 71% of the market, the math roughly matches.

[rgbrenner]

I think those market share numbers are suspicious.. according to rackspace they had 1.3b in sales of private cloud and public cloud services in 2012: http://ir.rackspace.com/phoenix.zhtml?c=221673&p=irol-ne...

So either the total is more than 100% market share for the 3, or those numbers or wrong.

Edit: added "in 2012" for rackspace financials

[mckilljoy]

I'd agree, most of these numbers are "fuzzy" and based on analyst estimates; I'd almost be more surprised if they DID perfectly add up to 100%. :-)

[ig1]

The percentages aren't market share rather percentages of companies using the product. That is a company which uses both Azure and AWS could contribute towards both percentages.