After buying Skype (or a little bit before that, don't know exactly) Microsoft converted into BIG Data operational philosophy. Same as Google and Facebook are following. In a nutshell they need every detail they can get on you and figure out the question they want to ask about that data later. That is why, in my opinion, they are pushing so hard the MS Account, Metro, always online Kinect in XBOne, etc. They are behind the curve with their uber database of entire earth human population and want to get more data.
Don't take this as lamentation about privacy. Any privacy when you are plugged to the net is illusion, at best. I'm just pointing out that this is approximately the same as Google, Facebook (and many other smaller players) are doing. In the case of MS we just kinda get somekind of kneejerk reaction if THEY are doing it as this has not been as obvious in XP and in the case of 7. When Vista and 7 came out there was a lot of discussion already about privacy and DRM and stuff as a lot of people seemed to see some of the stuff done in Vista and 7 as "locking things down". And in a sense it was - we just got used to it.
With various windows platforms still being approximately 95% of the market (at least according to Steam HW survey data) they are already pretty much rolling in data. Already approx 20% of home users are on Windows 8. Probably not quite as high number of devices yet as Android users but I'd imagine it's already large enough to allow MS to somehow monetize the data, especially in combination with data from Skype, Bing, OneDrive (as they call it now) and XBOne installations as well.