According to the data compiled by AdDuplex, more than 10 million Windows Phone handsets were sold in the last quarter, which includes holiday sales. To get to that figure, Mendelevich asks us to make the rather easy assumption that there were very few Windows Phone 7 sales. He bases his stats on an estimate of the number of Windows Phone 8 devices in use, which he computes at 35 million as of the end of the fourth quarter
The most important conclusion made by AdDuplex is that on a sequential basis, more Windows Phone handsets were rung up in the fourth quarter than during the third quarter, which would seem to contradict Nokia's earnings report. And yes, if AdDuplex is right, it would mean that the platform does have that good ol' momentum that could carry through into 2014. The problem is that Nokia should be seen as a more accurate provider of sales figures than numbers from a mobile data network, which are estimated based on ad impressions.
source: AdDuplex via WMPoweruser