Much faster than usual, the number of Windows Phone integrated Facebook users increased by another 100,000 to 1,800,000. While in recent months it has usually taken around 21 days for this number to increase by 100,000, it only took 15 days on this occasion.
Using our usual ratio this translates into more than half a million additional users over the last 2 week period and around 12 million active Windows Phone users in total.
Of course this number excludes Chinese Windows Phone sales, who do not benefit from integrated Facebook functionality.
Using Facebook numbers sales still seem to be on track for >3 million new Windows Phone sales, although with the recent acceleration this number may reach up to 4 million.
Thanks JP for the tip.