You can't turn on the TV, Internet or open a publication without encountering an ad for Windows Phones. And there are conflicting data about whether it's working and the corresponding strength of Windows Phone sales.
Several data sources continue to indicate tepid demand in North America but there is also some evidence that Windows Phone sales may be going reasonably well in certain parts of the world. The blog WMPoweruser identifies growth in the usage of Facebook apps for Windows Phones and extrapolates an increased sales trend on that basis:
Using the number of Monthly Active Facebook users as a guide, we can see around 627,000 MAU of the built-in Facebook app has been added since the 1st October 2012, the start of the quarter.
Last year over the same period less than 150,000 was added by the 15th December, possibly hinting at the source of Steve Ballmer’s statement that “Windows Phones are so far selling at four times the rate of the same time last year” Last year according to Gartner, who claims to measure units actually sold to end users rather than shipments, said 2.759 million Windows Phones were sold in Q4 2011.
The data suggests already 7 million Windows Phones were sold so far this quarter, and we may finally be heading to a + 10 million Windows Phone quarter.
If in fact Windows Phones were to sell 10 million units to end users it would indeed be a breakthrough for the beleaguered platform. However there's other data to suggest that Windows Phones are not doing as well as that. For example, the most recent comScore US mobile market share data show that Windows continues to lose overall share to iOS and Android:
There are also recent sales data from Kantar Worldpanel that show Windows Phones losing share in accordance with the comScore data above:
However in Europe Windows Phones are making some inroads, probably as a result of Nokia's promotional efforts and legacy brand strength. While the EU5 shows a 4.7 percent market share (growth of 1.7% vs. a year ago) individual countries vary widely.
In Italy, Spain and the UK Windows Phones have performed better than in Germany and France. In Italy in particular Windows Phones have gained almost 8 points and now stand at an 11.7 percent share of recent sales according to Kantar. Again, this is probably on the strength of the Nokia brand in Europe.
Elsewhere around the world Windows Phone sales appear to be modest. However in "urban China" Kantar says Windows Phones contstitute 4.2% of all recent smartphone sales.
It is possible that all these sales combined represent several million units around the world. But while there does seem to be momentum in certain countries it doesn't yet appear that this is a 10 million unit "breakthrough quarter" for the operating system.