Samsung's Gear VR headset may be the reason for strong Galaxy S7 growth. Source: Samsung.

Good news for Samsung (OTC:SSNLF) and Android fans. The company's new Galaxy S7 and Galaxy S7 Edge is a hit. The company recently pre-announced first-quarter earnings, and the results are better than anticipated. Samsung guided to $5.7 billion versus analyst expectations of $4.8 billion in operating income. Samsung also exceeded top-line expectations by guiding for $56.4 billion in revenue, greater than the $56.1 billion analyst consensus.

For investors in the United States, Samsung's consolidated earnings report is of little direct value. The company does list shares on the Gray Markets, the stock symbol above, but the investment is plagued by high bid-ask spreads, and low liquidity.

However, if you're an investor in Apple (NASDAQ:AAPL) either directly or through mutual funds or ETFs, following Samsung -- especially the company's mobile division -- will better help you evaluate the entire high-end smartphone landscape. It's well established that Samsung is the biggest competitor to Apple in the high-end smartphone market, and Apple's iPhone line is highly important to the company as an investment. In a slowing smartphone scenario, market share and competitor performance become inherently more important.

What smartphone growth slowdown?
It seems Samsung has a strong iPhone competitor in the newest Galaxy S7 line. According to early estimates, the current-generation unit shipped 9 million units in its first month, triple that of the prior-gen Galaxy S6, Bloomberg reports. Both units employ a similar form factor, but Samsung's newest version reintroduced popular features left off the Galaxy S6, including the microSD slot and waterproof design.

Additionally, Samsung sweetened the pot by bundling its new virtual-reality Gear headset with Galaxy S7 preorders. As a result of strong Galaxy S7 sales, Bloomberg estimates Samsung's heavily watched mobile division increased operating income 19% in the quarter.

Apple has been working on a VR headset on its own. Source: Patently Apple.

It would benefit Apple to understand how Samsung was able to grow its unit shipments. Waterproof design and the microSD slot were included in both the Galaxy S4 and Galaxy S5 iterations. That leaves the virtual-reality bundling as the biggest variable.

If Samsung is able to triple high-end sales against the backdrop of a smartphone market that is only expecting to grow 7% on a year-on-year basis, it would behoove Apple, Samsung's biggest competitor, to find out how the South Korean electronics conglomerate accomplished this growth. If VR is that big of a game changer, Apple should look to add this functionality to its next-gen iPhone.

It's hard to grow once you're Apple
To be fair to Apple, it's slightly disingenuous to compare Samsung's first-month total of 9 million to Apple's iPhone sales figures. For a comparison, Apple sold 13 million of the iPhone 6s and iPhone 6s Plus units in the first three days of availability. Overall, Apple sold 74.8 million units in the seasonally heavy first fiscal quarter.

Unfortunately, this huge figure was flat on a year-on-year basis, and has fueled concerns that Apple is no longer able to grow its top line at the rapid clip investors have become accustomed to. The company will certainly not report shipping three times the number of smartphones it shipped last year anytime in the immediate future.

During the first-quarter conference call, Apple CEO Tim Cook predicted a year-on-year iPhone unit sales decrease in the second quarter. The company has been big on growing its market share by stealing market share from what Cook refers to as "Android Switchers."

Samsung's surprising sales growth may reverse that trend and present further risks to iPhone sales. Don't look for Apple to recreate Samsung's amazing growth when it reports later this month, but it does show there's still demand for high-quality devices.