While the holiday shopping season is likely to bring good news for Apple (AAPL -0.57%) investors, two bits of information were released this week that investors should already be pleased about.

iPhone 5s. Source. Apple.

The first is that Apple just reported that adoption rates for iOS 7 are at a staggering 74% now. That's for all devices running the software, including iPad, iPhone, and iPod Touch. After Apple launched iOS 7 back in September, the number of iOS 7 devices outnumbered iOS 6 devices in just 72 hours. Apple said it was "the fastest software upgrade in history."

iOS 7 share. Source: Apple.

The company's high adoption rates speak to both the control Apple has over its devices and the high engagement Apple users have with their devices. iOS was one of the biggest software changes to its mobile devices since the iPhone launched, and the adoption rates and generally positive reviews speak to its success.

For a bit of comparison, Google's (GOOGL 0.35%) Android version Jelly Bean launched in July 2012 and runs on 54.5% of Android devices. The latest version of Android, called KitKat, launched a month ago and runs on just 1.1% of Android devices.

Google has long experienced fragmentation problems across its versions, mostly because carriers and manufacturers are largely responsible for updating the device software. Apple, on the other hand, has nearly complete control over when and how its software is updated.

Apple still tops U.S. smartphones
Aside from its growing iOS adoption rates, recent comScore data shows that Apple's iPhone still makes up the vast majority of smartphone subscribers in the United States. In the three months ending in October, Apple made up 40.6% of smartphone subscribers, while Samsung (NASDAQOTH: SSNLF) had 25.4% and Motorola nabbed 7%. Apple's position was up from 40.4% in July of this year, while Samsung moved up from 24.1%. While Apple's increase wasn't huge, the company still holds a large lead over Samsung and far outpaces any other original equipment manufacturer.

One interesting thing to point out is that the comScore data includes the launch of both the iPhone 5s and 5c. Considering that two new phones launched, and that the 5s had significant upgrades over the iPhone 5, Apple's increase in U.S. smartphone subscriber percentage seems bit low. Samsung didn't launch any major smartphones between July and October, and the company made more gains than Apple did over that time period. It's possible the holiday shopping season could add to Apple's subscriber share, but it's something investors should take note of. Apple's top OEM position in the U.S. doesn't seem seriously threatened by Samsung right now, but any incremental increases by the competition shouldn't be taken lightly.