While Microsoft fans are deliriously trying to paintApple’s quarterly earnings announcement as some form of bad news—iPhone sales were flat, after all, and iPad and Mac sales fell, in the former case for the 8th straight quarter—let’s get serious. This is the most successful company in the world, and it’s only natural that sales of its blockbuster primary product would slow—even fall—over time.

To put this in perspective, considerthis one fact (it’s not afactoid, which is a lie): Apple’s “active installed base” is now one billion devices. This is:

iPhone, iPad, Mac, iPod touch, Apple TV, and Apple Watch devices that have been engaged with our services within the past 90 days.

The use of the term “active installed base” is interesting, because installed base is “usage,” what I callreal or engaged usage, and not “sales” or “installs.” And because this is similar to the metrics that both Google and Microsoft use for their Android devices and Windows 10, respectively.

Granted, some of those Apple devices were probably sold into the market place years ago. But that 1 billion figure can and should be compared to the numbers Microsoft touts for Windows 10 (200 million, most recently) or Windows more generally (1.5 billion active users, a number that hasn’t moved, magically, in years), and that Google touts for Android (over 1.4 billion, as of September).

My understanding of iOS is that the user base was previously thought to be around 800 million strong, and when you factor out Macs and other non-iOS Apple devices, that’s probably about right. But as you can see, there are three big personal computing platforms. And only one of them is actually declining. We’ll see how Windows 10 fares over the long term, but even if Microsoft hits the 1 billion figure in 1-2 years as promised, it will by then still be the smallest of those three platforms.

This is just for perspective, and a reminder of why Microsoft is pushing so hard on rival mobile platforms. You simply can’t ignore personal computing platforms as big as Apple’s and Google’s.