Windows Phone 7 devices made their U.S. debut Nov. 8, once the quarter was already underway, and continues to be unavailable on Verizon and Sprint. That would hobble any new platform's market-share, even without Apple's iOS and Google Android sucking all the oxygen out of the proverbial room. Plus, despite its creaky nature, Windows Mobile remains a legacy player among a not-insubstantial subset of businesses--a presence that, like Windows Vista, could take some time to fully dwindle to nothing.
If anything, the NPD Group data simply confirms the obvious: Windows Phone 7 is not a breakout hit. For months ahead of the platform's release, Microsoft executives had been prepping for that eventuality, telling anyone who would listen that Windows Phone 7 was a long-term project unlikely to beat Android or iOS anytime soon.