Google Cloud just reported revenue for the first time – but it's hard to compare with Amazon and Microsoft because there's a lot they don't tell Wall Street about their clouds (MSFT, AMZN, GOOGLE)

· Google Cloud just reported revenue for the first time.
· Google's cloud unit brought in $2.6 billion in its most recent quarter, compared to Microsoft's $12.5 billion and Amazon's $9.9 billion – but there's a big flaw in that comparison because the companies report cloud revenue differently.
· Microsoft doesn't report...