Big numbers are back in the news, as Microsoft confirms there are now nearly 700 million devices running Windows 10. Microsoft, of course, had an original target of one billion devices running Windows 10 within three years of its launch.
That gives it until the end of July to hit that magic one billion, which is looking very unlikely considering its current trajectory, although really it's long been assumed that Microsoft was going to miss this goal, largely because of its decision to pull out of smartphones.
When the one-billion goal was floated in 2014, Microsoft had acquired Nokia's smartphone business and was positioning Windows 10 on mobile as an alternative to Android and iOS. But the promised breakthrough never came and Microsoft swiftly exited the smartphone business.
Big numbers matter: getting as many users onto Windows 10 makes it easier for Microsoft to roll out new services faster and helps it move towards its vision of Windows as-a-service, and encourages developers to build for it too. It's also worth remembering that there are plenty more PCs out there running Windows of one sort or another -- somewhere north of a billion.
So how do the numbers for Windows compare with the two other big device ecosystems, Android and iOS? Reasonably well, it seems, especially when you look at both the total install base and the numbers using the latest versions of the operating systems.
In February, Apple said it had an active install base of 1.3 billion devices including Macs, iPhones, iPads, Apple Watches.
Now it's hard to know how many of that total are iOS devices -- somewhere around 100 million or more are Macs, for example. But Apple says 76 percent of devices accessing its App Store are running iOS 11. That would suggest the total number on the latest version of iOS is between 700 and 800 million.
As for Android, last year Google said it had two billion active Android users, so that number is likely to have increased. But these users are spread across many different versions of its very fragmented operating system.
Even the most popular version of Android, Nougat, released in August 2016, only has a 31 percent market share, which would mean it has around the same number of users as Windows 10.
Android Marshmallow, launched around the same time as Windows 10, accounts for about a quarter of all Android users. Android Oreo, launched last summer, has a mere six percent of Android users.
But what comes next?
For the past few years the momentum has been with Android and iOS because we have been buying fewer PCs. That may be about to change as the smartphone market also rapidly reaches saturation. As sales and profits plateau, these tech giants will be looking for the next big thing.
Most of the large tech companies are betting that some kind of virtual-reality or augmented-reality smart glasses will be the next breakthrough when it comes to devices.
Microsoft has HoloLens, while Apple's smart glasses project is under wraps but some details have already emerged. Google has been experimenting with varying success for quite some time.
One big question; can these giants use those vast numbers of customers they've built up to ride the next technology wave successfully? It's clear they were all caught flat-footed by the rise of the smart speaker and digital assistants popular in the home. Amazon seized that opportunity and ran.
It had a different type of user base, one made of hundreds of millions of shoppers. Another big rival coming up on the rail is Facebook, with two billion users and every indication of being very interested in AR and VR.
Having a captive audience in the form of a big install base of hardware users has always been the key to success. The question now is will that remain true when the next big thing comes along.
Microsoft won the desktop, Google and Apple won the smartphone, and it looks like Amazon is winning the smart home. Who wins next?
ZDNET'S MONDAY MORNING OPENER
The Monday Morning Opener is our opening salvo for the week in tech. Since we run a global site, this editorial publishes on Monday at 8:00am AEST in Sydney, Australia, which is 6:00pm Eastern Time on Sunday in the US. It is written by a member of ZDNet's global editorial board, which is comprised of our lead editors across Asia, Australia, Europe, and the US.