How credible could it be, though? Unofficial reports claimed early sales of some 40,000 Windows Phone 7 devices. The number is far from ground-breaking, but shortages have also been reported in various places, which hints that handsets with the new OS are not actually selling bad. Redmond has invested significant effort and funds into pushing app development for Windows Phone 7 and latest reports show its Marketplace grew steadily to 3,000 available apps and around 15,000 registered developers. In any case, we are left to guessing until Microsoft speaks up and this might happen at CES in January. Hold on until then and do not be surprised if the number is far from the Facebook-based estimates.
Growth of active users of the Facebook app for WP7