In today's world, most companies span several regions and sell across the world. As Foolish colleague Morgan Housel notes, 10 years ago, less than a third of S&P 500 revenue growth came from abroad. Today, that area makes up half of the S&P 500's growth.

And that number is growing. The truth is, investors regularly underestimate how much demand comes from abroad. More importantly, for large, multinational corporations that have already established a presence in their home markets, much of their future growth comes from abroad.

With that in mind, today we're looking at Nike (NYSE: NKE). We'll examine not only where its sales and earnings come from, but how its sales abroad have changed over time.

Where Nike's sales were three years ago
Three years ago, Nike produced 41% of its sales within North America. Western Europe also produced strong results, totaling 27% of the company's sales.  

Source: S&P Capital IQ.

Where Nike's sales are today
Today, North America is still Nike's largest market, but its sales geography is rapidly changing.

Source: S&P Capital IQ.

While the North American percentage held steady, Western Europe continues to be a less relevant geography for Nike. In fact, when combining Greater China and the Emerging Market region, those two geographies are now almost as large as Nike's entire European operations! Give those regions another year and they'll begin far outstripping Nike's operations across Europe.

That's an amazing sea change and shows the stunning opportunity ahead for consumer brands like Nike that have managed to move across the globe. The challenge for competitors like Under Armour (NYSE: UA) and lululemon (Nasdaq: LULU), a company which I recently featured in this series, is to learn from Nike and expand their own clothing lines across multiple geographies to reach a much larger audience.

The closest competitor to Nike would likely be Adidas. However, the scary part of Adidas' story is the company's lack of growth over the past three years in its home Western European market. While Nike has seen European sales shrink as a percentage of its overall revenue, Adidas has far more to lose if the continent's spending malaise continues. Another scary fact for Adidas investors is that Nike has grown more than 52% in China over the past three years while Adidas has grown just 6% in the country over that time.

Keep searching for global opportunities
There's a reason companies are seeing outsized growth around the world; in the past decade emerging-market consumer spending grew 250%, leaving the growth rates of the U.S. and Europe in the dust. If you're an investor scanning the world for opportunities, look no further than our new report "3 Companies Set to Dominate the World." In the report, Fool analysts select three companies who have an international growth opportunity that's simply stunning. The report is free but won't be available forever, so get your copy by clicking here today!