I watched a really interesting talk about how XBox (and presumably the Xbox One) uses a technology they call TrueRank to do player matching. As far as I know this was an MSR project to create a Bayesian version of the ELO chess ranking system. Actually, now that I think of it, it was a whole week of ML talks by academics from MSR.
My point being, they produce (and ship) a lot of smaller innovations too, behind the scenes. Sometimes it's just detecting griefers.