Try as it will to break through in the mobile space, Microsoft is still struggling to gain any ground with Windows Phone almost a year and a half after its launch.
Things have gotten so bad that that in a recent market share report by research firm Nielsen, Windows Phone market share was so small in the U.S. that Nielsen didn't even bother to break out its usage. It was relegated to the dreaded "other" category.
Well at least there's the dominant Windows client OS, right?
Source
A Guy