Microsoft announced this week that Windows 10 has spread to over 200 million devices since its launch last year, and Windows expert Mary Jo Foley estimates that roughly 18 million of those devices are Xbox One consoles.
This potentially sheds some light on how many Xbox One consoles have been sold to date, which is notable given that last October Microsoft stopped regularly reporting console sales numbers in favor of focusing on "engagement" statistics.
Competitor Sony, incidentally, has continued to report console sales, noting earlier this week that PlayStation 4 is coming up on 36 million units sold worldwide.
However, Foley's comments on Xbox One -- made during this week's episode of Windows Weekly -- come with significant caveats. She notes that the "around 18 million" estimate comes from an anonymous (but presumably trusted) source, and that it refers specifically to the number of Xbox One consoles running Windows 10 that were active within the past 28 days.
Microsoft began rolling out the Windows 10 update to Xbox One consoles last November, so this estimate presumably does not account for sales of Xbox One consoles that have not been connected to the network since before that update's debut.
Still, it seems likely that the vast majority of Xbox One consoles sold to date are also connected to Xbox Live, given that competitor Sony noted in 2014 that "more than 90 percent of PS4s in the U.S. are connected online."