Based on the number of active users of the official Windows Phone 7 Facebook app, The Next Web has estimated that Microsoft has notched up two million sales of Windows Phone 7 phones. When Microsoft announced that its hardware partners had shipped 1.5 million Windows Phone 7 phones, there were around 209,000 active users of the Facebook app. Using this method, it seems that Microsoft has reached the 2 million milestone over the holiday period, shifting another 500,000 units.
