Did AT&T and Verizon Give Up More iPhone Hints Ahead of Apple Earnings?

This week was destined to be a big one for Apple (AAPL 1.27%). Yesterday, the Mac maker unveiled its new iPad mini alongside a handful of new redesigned Macs, with pre-orders of the smaller tablet starting on Friday. Tomorrow, the company will report its fiscal fourth quarter earnings after the close, and all eyes will be on how many iPhones and iPads it was able to move.

The top two
Apple's two biggest domestic carrier partners, AT&T (T 1.88%) and Verizon (VZ -0.53%), have now posted their own respective earnings results, including iPhone activation figures. Third-largest carrier Sprint Nextel (S) will report its own earnings and iPhone activation numbers tomorrow, but can investors glean any clues from the digits that Ma Bell and Big Red just offered up?

Sources: Verizon and AT&T earnings press releases and conference calls.

Between the two largest domestic carriers, we're looking at 7.8 million iPhones activated in the calendar third quarter, representing 60% of all smartphones activated on AT&T and Verizon's respective networks. The median estimate among analysts is 27 million iPhone units, so investors can safely say that a quarter of these are already in the bag.

Sprint's figures tomorrow morning will add some more, but that will be just hours before Apple's big reveal. For context, in the three quarters since Sprint got its hands on the iPhone, it's activated 1.8 million, 1.5 million, and then another 1.5 million units, in that order. Both AT&T and Verizon put up sequential increases, so Sprint may approach 2 million iPhone activations.

A game is still just a game
Investors frequently try to use AT&T and Verizon activation figures and other clues to try and extrapolate overall iPhone unit sales, a game I play from time to time. While such numbers games may be fun while helping add some context to how realistic unit estimates are, investors need to recognize the inherent limitations there and shouldn't base investment decisions solely around them.

For example, leading up to earnings in April, Apple sold off by 2% that day on fears that carrier activations were weaker than expected. Shares proceeded to promptly rally by $50 per share, or 9%, the following day after the company posted a blowout quarter and beat the iPhone unit estimate by 5 million units.

If you look at the percentage of total iPhone unit sales attributed to AT&T and Verizon, separately and combined, you'll see it's anything but consistent.

Sources: Earnings press releases and conference calls. Percentages do not add due to rounding.

Over the past six quarters since Verizon first got the iPhone, the pair's combined activations as a percentage of the total has ranged anywhere from 21% to 31%, with 25% being the sum most recently. Extrapolating based on those percentages implies total iPhone unit sales of 37 million, 25 million, and 31 million, respectively.

That's a pretty wide range that goes to show just how limited such an approach really is.

Reality bites
In reality, investors need to keep in mind that this quarter's iPhone unit sales will be dramatically affected by consumers awaiting the launch of the iPhone 5, potentially delaying purchases. The iPhone 5 was launched with just nine days left in the fiscal quarter, and was immediately stricken with supply constraints that are persisting to this day. Apple, AT&T, and Verizon have all officially acknowledged that these constraints are holding back the iPhone.

If Apple does miss the 27 million iPhone unit median estimate, I would attribute any shortfall to a combination of these factors. The key thing for investors to remember though is that all of these shortfalls are short-term in nature, and the bigger picture remains fully intact.