The life-time sales of Microsoft's Xbox One gaming console stand at at-least 18 million. This was recently revealed by ZDNet's Mary Jo Foley citing a source with knowledge of the matter, although she said she couldn't verify the figure.
Foley made the revelation at the latest episode of the Windows Weekly podcast while giving the breakdown of the 200 million Windows 10 devices - Microsoft recently revealed that more than 200 million monthly active devices worldwide are now running the OS.
As she was dissecting that 200 million figure, so it's worth stressing that the 18 million Xbox One number includes only those consoles that Microsoft says are "active," a term which refers to devices that have been active in the last 28 days.
Meanwhile, Sony recently revealed that a total of around 36 million PS4s have been sold until now, including 5.7 million that the Japanese company sold this past holiday season alone.