So far they've only lost money with Surface. And I remember they were saying to their partners initially "don't worry, this is just a reference product - it's like not like we're actually trying to compete with you or anything like that!" - yet they're now at the third iteration.
Microsoft has the right product for those of us that would like rather have a laptop capabilities with the size and battery duration of a tablet.
iOS and Android ecosystems require a big brother computer for proper application development, whereas on the Surface I can change to desktop mode and run Visual Studio with the full SDK.
This is what has putted me off to buy a Android Asus Transform a few years ago and buy a Asus Netbook with Ubuntu instead.
