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

And that number is growing. The truth is that 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 Australian miner BHP Billiton (NYSE: BHP). We'll examine not only where its sales and earnings come from, but how its sales abroad have changed over time.

Where BHP Billiton's sales were five years ago
Five years ago, BHP Billiton’s largest market by far was Europe.

Editorial

Source: Capital IQ, a division of Standard & Poor's.

The company collected 35% of sales from the European market, while its next closest operating segment, China and “other” Asian countries, both collected 13%. The combined total of all end shipments to Asia was 38% of the company sales.

Where BHP Billiton's sales are today
Today, BHP Billiton’s sales have changed dramatically. Fueled by surging demand for raw materials in emerging Asian economies, sales have boomed in the past five years. In BHP’s fiscal 2010, Asian sales increased all the way to 54% of the company’s total. Europe, which generated 35% of company sales in 2005, has sagged all the way down to 19%. The chart below breaks down BHP Billiton's current sales by geography.

Editorial

Source: Capital IQ, a division of Standard & Poor's.

Competitor checkup
One last point to check is how BHP Billiton's footprint compares to some of its peers across the broader metals and mining industry.

Company

Geography With Most Sales

Percent of Sales

BHP Billiton China 25%
Freeport-McMoRan (NYSE: FCX) United States 28%
Rio Tinto (NYSE: RIO) China 30%
Vale (NYSE: VALE) China 33% 

Source: Capital IQ, a division of Standard & Poor's.

Not surprisingly, BHP Billiton’s closest peers -- Vale and Rio Tinto -- have seen China eclipse other markets as their largest end sales location. That’s in large part due to soaring demand for iron ore. An investment decision in any of the three largest iron ore companies will have to focus heavily on your perceptions on the sustainability of China’s continuing high economic growth rates.

Keep searching
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Eric Bleeker owns no shares of any companies listed above. 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.