Microsoft's mobile phone platform is a distant fourth in what is basically a four horse race. Android has over half the market right now, and the iPhone has over half of what is left. Blackberry is in third. A year after launching, Windows Phone 7 hasn't yet broken the 10% share barrier. When you look at Facebook usage though, it looks like Microsoft is enjoying a surge in recent weeks that dramatically changes its growth curve.

By tracking the number of active users on Facebook using the Facebook integration features in WP7, it shows an increase of 100,000 users between November 11 and November 25. Based on calculations that took Facebook usage and compared to the last time Microsoft released stats, WMPowerUser thinks this could mean 600,000 new users in the last two weeks.

That is a small number compared to Android and even iPhone sales, but it is a big number for Windows Phone. This isn't so much about the numbers as it is about the change in the growth curve. On average, there have been about 100,000 new Windows Phone Facebook users per month. Now it looks like that is doubling. There are a few things that could be at work here. First of all, Mango shipped in October and that has spiked interest in the platform due to the coverage in tech blogs. In Canada, "Windows Phone 7" was the eighth most searched for consumer electronics item on Bing, and it was ninth in the U.S.

Nokia has also released its first WP7 phone, the 800, and that may be directly contributing to the surge. If that is true, Nokia may yet be WP7's salvation.

The real question, though, is whether this is an anomaly or a trend that will continue. That is, of course, anyone's guess. It will be January or February before we see some solid analysis on fourth quarter numbers. If they don't back up this growth spurt though, it will bring the whole Nokia/Microsoft marriage into question, as well as the future of Windows Phone.

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