Apple's latest mobile operating system might be its most popular yet.
The company announced via press release Monday that more than 50 percent of iPhones and iPads have upgraded to iOS 9 in the days since its release.
That's a bit more than usual. At the same time last year, 46 percent of devices had upgraded to the latest release, iOS 8.
Here's why iOS 9's popularity matters: As long as Apple continues to find success with its annual updates, iPhone users are going to face the same couple questions year in and year out: "Should I update? Will this make my phone slower?"
The answers are a little more complicated than you might expect, and they mostly hinge on how old your iPhone is. Apple ensures that its latest iOS releases work best on its new hardware, as we pointed out last year, meaning in this case that iOS 9 will run smoothest on the shiny new iPhones that come out this Friday.
If your device is at least two years old -- in this case, an iPhone 5S or older -- upgrading to iOS 9 might leave you with a slower phone. But not updating will eventually leave you in the dust when it comes to app updates, since developers start programming for the latest version of the operating system. So, perhaps you get frustrated and purchase a new iPhone, and the cycle continues.
Suffice it to say, Apple is adept at creating reasons for consumers to shell out cash over and over again for new iPhones.
Of course, if you're inclined to upgrade, there are a number of nice new features in iOS 9. There's a "low-power" mode to improve your battery life, notifications are sorted differently to help you see the latest and there's a security update, to name a few. (Gizmodo's broken down plenty more.)
H/T The Verge