Even as more and more companies sell their goods and services worldwide, investors still underestimate how much of those businesses' demand -- and potential growth -- comes from abroad.

As my Foolish colleague Morgan Housel notes, S&P 500 companies earned just one-third of their revenue outside the U.S. a decade ago. Now, more than half of the S&P 500's revenue growth originates abroad -- and that figure's still growing.

With that in mind, today we'll examine where Starbucks' (Nasdaq: SBUX) sales and earnings come from, and how its sales abroad have changed over time.

Sales then and now
In 2005, Starbucks collected a hefty 84% of sales from within the United States

Sbux

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

Today, Starbucks is remaking itself as an international company. The United States now accounts for 78% of sales -- still a majority, but down 6 percentage points from its 2005 total.

Sbux

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

In an interview last year, Starbucks' CFO Troy Alstead emphasized the company's Chinese efforts. Subsequently, Starbucks kept highlighting international operations as an "enormous opportunity" in investor presentations.

In addition to opening more stores abroad, Starbucks also wants to sell more of its consumer products through foreign channels. Via instant coffee proved a quick success in the U.S., and could do even better foreign markets. As Starbucks proudly notes, instant coffee represents more than 80% of retail coffee sales in both the U.K. and Russia.

But where are the profits coming from?
Fools should also consider whether Starbucks' international moves actually generate substantial profits. In 2010, the company recorded $225 million in operating profit before taxes, compared to only $91.2 million the year before. That's a 146% jump in profits on a 19.4% jump in sales. While that owes partly to operating leverage, it also stems from targeted cost-cutting moves abroad. As I wrote last year:

Troy [Alstead] also spent some time discussing Starbucks' international plans. The company wants to leverage its back office across several countries to make its international presence more cost-effective. For example, it is consolidating back office operations between France, the U.K., and Germany.

Both at home and abroad, the company managed to cut costs significantly this past year.

Competitor checkup
Finally, let's see how Starbucks compares to some of its peers across the broader restaurant business:

Company

Geographic Area With Most Sales

Percent of Sales

Starbucks United States 78%
Green Mountain Coffee Roasters (Nasdaq: GMCR) United States 97%
McDonald's (NYSE: MCD) Europe 40%
Tim Hortons (NYSE: THI) Canada 95%

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

Not surprisingly, Starbucks' international exposure falls well short of McDonald's, but lands ahead of Canada-centric Tim Hortons and Green Mountain Coffee Roasters, which currently only record revenue for the United States and Canada.

Keep searching
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