Many see online as a "loss-leader", consider it setting out your stall. MS makes plenty of cash from selling product, but you could argue without the online presence their sales would be diminished - so where they are on the balance is what really needs to be considered i.e. if they shut up shop online, what the cost to the OS/Office division would be now and in the future?

There is always the hope to tough it out in the hop of eventually gaining more market share as your competitors run out of steam and cash.