My guess is that they gave it a try and the purchase volumes never materially compared to credit card payments. Integration was done very poorly. You had to go

My guess is that they gave it a try and the purchase volumes never materially compared to credit card payments. Integration was done very poorly. You had to go to a special link "commerce.microsoft.com" and click on a small, un-styled link at the bottom of the page called "Redeem bitcoins". It was never integrated in to their main purchase flow in an easy way. It couldn't be found just by chance. You had to google to figure out how to fund with bitcoin. Edit: There are a handful of comments about price fluctuation. Microsoft liquidated to USD right away using a company called BitPay. BitPay would take on the short term price risk and Microsoft would get exactly what they quoted in USD. Microsoft was not subject to BTCUSD price fluctuation in this scheme.