Parsing Microsoft's Decision to Cut Windows Fees - NYTimes.com

Check the full article for reasons why this is a reasonable opportunity cost equation for Microsoft

"Microsoft said it would no longer charge a fee to hardware makers that want to put Windows on devices with screens that are smaller than nine inches. It was said to be getting somewhere in the range of $15 in revenue each from such devices.

What that means, in practical terms, is that Microsoft will no longer make any direct Windows revenue from smartphones and smaller tablets."

Parsing Microsoft's Decision to Cut Windows Fees - NYTimes.com