Microsoft is paying top dollar for MarkMonitor, aren't they supposed to proactively register obvious typos so this kind of thing doesn't happen to their clients?

My guess is that MarkMonitor is mainly used for their brand-relevant domains (microsoft, office 365, github (main site), etc), as opposed to one that a small subset of a small subset of their users of one service will use - I would imagine that microsoft likely owns hundreds of domain names and doesn't pay MarkMonitor to monitor every single one