It is easy for investors to count out Netflix (NASDAQ:NFLX) stock as a potential investment, pegging it as an overvalued high-flyer -- even after the stock's 15% sell-off in the last week. However, investors shouldn't stop their analysis at intimidating pricey valuation metrics. There's a solid growth story for this scalable market leader and it's looking like 2016 will be a key catalyst.

Netflix Nflx

Image source: Netflix.

Will Netflix subscribers hit 100 million next year?
A close look at Netflix's recent member additions reveals something intriguing and exciting. Driven by international expansion, successful Netflix originals, as well as secular growth in Internet TV adoption, member growth is picking up considerable steam. For instance, in the trailing twelve months, Netflix added 15.5 million new subscribers, ahead of its 12.5 million subscribers added in the preceding trailing twelve months. And, going forward, this trend looks set to continue. The company is forecasting its Q3 net member additions will be 18% higher than its additions in the year-ago quarter.

At this rate, it's quite possible that Netflix could reach 100 million members, up 53% from its 65.5 million subscribers today, by the end of next year. And a catalyst to help Netflix achieve this impressive milestone is just around the corner.

Netflix' enormous wildcard: International expansion
To date, Netflix' international streaming business hasn't contributed anything meaningful to the company's bottom line. On the contrary, the segment has actually diminished profitability. The segment consistently reports a contribution loss as the initial costs of expanding surpass revenue in these newer markets.

Nonetheless, investors shouldn't overlook the potential in Netflix' international segment just because of its inability to contribute meaningfully to the company's business today. The streaming giant's business is proving to be scalable in these markets, too. But of course, it's going to take time. And for investors looking for early signs of upside potential abroad, management said in Netflix' second-quarter letter to shareholders that its first set of international markets are already achieving contribution profitability.

Given the sheer size of Netflix' international expansion plans, the company's international business could someday create a contribution profit rivaling the U.S. market.

Already, Netflix' international streaming revenue accounts for a notable 28% of the company's total streaming revenue. However, this figure will likely grow over time. The company's net international additions are now surpassing domestic additions. For instance, consider the company's Q3 guidance for 2.4 million international additions and 1.15 million domestic additions.

Looking into 2016, Netflix's quarterly net additions could be significantly higher. Not only is Netflix planning to launch in the important Chinese and Japanese markets, but also the company is planning to enable people in nearly every country on earth to use the service by the end of next year.

Combining continued success with Netflix originals, secular growth in Internet TV viewing, as well as an ambitious plan for international expansion, the company's growth looks poised to continue to be strong.

Daniel Sparks has no position in any stocks mentioned. The Motley Fool owns and recommends Netflix. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.