The latest tracking stats for Windows phones have been released by advertising network AdDuplex, which monitors usage across its network to create a detailed monthly breakdown of Microsoft's mobile ecosystem. Each month, the reports capture a snapshot of worldwide usage across one 24-hour period - in this case, November 21, 2016.
This month, AdDuplex has focused almost exclusively on the US, partly due to the fact that "not much is happening in the mobile world of Windows in general".
As AdDuplex points out, "growth of Windows 10 Mobile share has stalled worldwide in the last couple of months and [the] US is no exception." Eight months after its release, just 15% of all active Windows phones in the US are running Windows 10 Mobile, with a staggering 80% of devices on Windows Phone 8.1.
While many of its Windows Phone 8.1 handsets are eligible to upgrade to the newer OS, Microsoft has made almost no effort to encourage users to do so. Instead of actively notifying them that they can upgrade to Windows 10 Mobile, Microsoft instead requires users to download an 'Upgrade Advisor' app from the Store - but in order to do so, users have to be aware that the app exists in the first place, and with no notifications from Microsoft, most people have no idea that the option to upgrade is available to them.
It's still unclear why the company has shown so little interest in getting users to install Windows 10 Mobile. As AdDuplex notes, "this presents a major obstacle in UWP [Universal Windows Platform] adoption for mobile-first Windows apps".
Of those few devices running Windows 10 Mobile in the US, the most popular is the low-cost Lumia 640, which has been sold there for as little as $26.99 with no contract. The flagship Lumia 950 - which Microsoft has given away free with the larger Lumia 950 XL, more than once - is just behind it. Notably, the 950 is available though AT&T, but the 950 XL received no carrier sales support in the US, pushing it into fourth place, behind the more affordable Lumia 650.
The Alcatel OneTouch Fierce XL - which was sold exclusively by T-Mobile, but has now been dropped - is the only non-Lumia Windows 10 Mobile device in the US top 10, slotting in at number 5. Between them, these five handsets account for just under 70% of all Windows 10 Mobile devices there.
Significantly, AdDuplex points out that the new Alcatel IDOL 4S with Windows 10 flagship - which is another T-Mobile exclusive, and went on sale less than two weeks ago - has already become the 16th most widely-used Windows 10 Mobile device in the US. HP's Elite x3, which is priced at $799 with a desktop dock, is at number 13. Given that Windows phone market share has been in steep decline for some time now, the rapid ascent of these high-end handsets is likely a symptom of low overall sales of Windows phones, rather than a firm indicator that these two devices have been a massive sales success.
While the Lumia 950 accounts for 19.3% of Windows 10 Mobile devices in the US, it represents just 3.8% of all Windows phones in use there. The Lumia 640 is the most popular Windows phone overall, while the ageing Lumia 635 takes the number 2 spot. Many of the devices in the top 10 are just as old, if not more so, including the Lumia 920, which was released at the end of 2012; and the Lumia 521, which launched a few months later.
Lumia handsets continue to dominate the Windows 10 Mobile landscape in the US, with almost 90% share of the platform. Alcatel has achieved 6.2% share - but bizarrely, 3.4% of Windows 10 Mobile devices appear to be from HTC, despite no support for the new OS on HTC's ageing Windows phones.
AT&T is the carrier of choice for US Windows 10 Mobile users, followed by Cricket, the value-focused carrier brand owned by AT&T.
12.4% of Windows 10 Mobile users in the US are on the Windows Insider Program, running the latest preview builds of the OS, but almost 10% of users are stuck on the original version of the OS from last year. 77.7% are on the most recent general release, the Anniversary Update - but worldwide, that figure is even higher, at just under 84%.
Things are bit more even on the Windows 10 desktop side of things, with roughly 83% of users in the US and around the world on the Anniversary Update. 0.7% of Windows 10 desktop users are Insiders.