Apple (NASDAQ:AAPL) stock recently got another upgrade, this one from RBC Capital Markets. Analyst Amit Daryanani maintained an "outperform" rating for Apple and raised his target from $100 to $110 on Wednesday. His reasoning for incremental confidence in Apple? Multiple levers that will drive revenue acceleration over the next several years. While some of the same catalysts Daryanani cites in his report are the same ones that other analysts frequently mention, one often gets overlooked: emerging-market penetration.

iPhone 5s. Image source: Apple.

In Daryanani's note to investors (via AppleInsider) on Wednesday, he emphasized a number of factors that will drive growth for the stock.

  • $164 billion in cash, or $22 per share.
  • The iPhone 6.
  • New iPad models.
  • New product lines, such as the rumored iWatch.
  • Improvements in capital allocation policies.

But the often overlooked potential lever for the stock, emerging-market penetration, deserves a closer look -- especially after Apple gave the catalyst some special attention in the its most recent earnings call.

"I'm especially happy about our progress in the BRIC countries, where iPhone sales were up a very strong 55% year over year," Apple CEO Tim Cook said during the company's third-quarter earnings call on Tuesday. 

While Apple doesn't break out all of these BRIC countries or other emerging and developing markets into their own segments in Apple's earnings reports, the company did provide some data that gives investors an idea of how successful Apple is currently in growing its sales in some these countries.

Apple store in China. Image source: Apple.

In India, China, and the Middle East, iPad sales were up 45%, 51%, and 64% from the year-ago quarter, Cook said during the most recent call. Furthermore, in Apple's second fiscal quarter earnings call, the company said iPhone sales in Brazil, Russia, and India were up 61%, 97%, and 55% from the year-ago quarter.

For China, the world's largest smartphone market, Apple provided a host of statistics in the company's most recent quarter for investors to chew on. First of all, the entire Greater China segment (which is separated out in Apple's operating segments and includes Hong Kong and Taiwan) saw revenue increase by 28%. Mac sales in China were up 39% from the year-ago quarter -- a market that Apple says was predicted by industry forecasts to contract by 5% during that period.

China Mobile -- the gift that keeps on giving
In the biggest of all of these emerging and developing markets, China, Apple has a major tailwind: China Mobile.

The bullish thesis for China Mobile as a meaningful tailwind for Apple's iPhone sales can be explained very easily. As the unquestioned dominant player in the high-end smartphone market in China (which includes smartphones priced at $500 and up), Apple is poised to benefit immensely from the rollout of China Mobile's 4G network. And as the world's largest carrier, with 790.6 million subscribers, the scale of this rollout makes the opportunity for Apple substantial.

Just look at the rollout so far.

Data for chart retrieved from China Mobile's monthly operating data.

While the vast majority of China Mobile's subscribers can't afford an iPhone, China Mobile's fast-growing base of 4G subscribers alone is key evidence that there is a substantial market for high-end smartphones at the carrier. And Chinese app analytics firm Umeng said earlier this year that, based on its data, $500-plus smartphones make up 27% of the market in China -- and 80% of those are iPhones. So when Apple gets plugged in to an exponential curve like this one, seen in the growth in China Mobile's 4G subscribers, there is some serious growth potential for Apple's largest and most profitable business segment at the carrier.

Kudos to Daryanani for giving the emerging-market penetration catalyst the credit it deserves. The catalyst is, indeed, an important lever for Apple stock.

Daryanani joins a host of other analysts who have recently upgraded their price targets for Apple stock. And even at a bullish $110 price target, he isn't alone. Four analysts who have upgraded their price targets in recent weeks have price targets for Apple stock of $110 or higher.