Source: American Tower.

American Tower (NYSE:AMT) recently reported results for the second quarter of 2014. The operator of 68,800 broadcast and wireless communications towers delivered a solid earnings surprise, and shares rose as much as 5.6% the next day. And don't call it a fluke: American Tower has consolidated those gains even further to set several new 52-week highs, with the latest one falling in last Friday's trading session.

In the second quarter, American Tower's sales rose 28% year over year to land at $1.03 billion. That's just ahead of analyst estimates at an even $1.0 billion. GAAP earnings rose 132% year over year, stopping at $0.58 per share. Analysts would have settled for $0.54 per share.

Organic core sales increased by 11% domestically and 18% in international markets, driven by demand for 4G signal coverage on a global level. Moreover, American Tower built or acquired a net of 357 new U.S. towers during the quarter. Overseas, the company added a net of 755 new towers.

59% of American Tower's sites sit on non-U.S. soil today, up from 44% just three years ago. The company is rapidly adding capacity to markets such as Chile, Brazil, India, and Mexico, often by making strategic plug-in acquisitions in these territories. These markets are growing faster than American Tower's domestic network.

By comparison, arch rival Crown Castle International (NYSE:CCI) relies almost exclusively on its American tower network. A total of 4.3% of Crown Castle's towers make up its fledgling Australian network, which is the company's only interest outside America.

Both strategies deliver solid revenue and cash flow growth. Do keep the fundamental difference in mind, since Crown Castle delivers a far tighter domestic focus than the internationally-minded American Tower.

AMT Revenue (TTM) Chart

AMT Revenue (TTM) data by YCharts

Looking ahead, American Tower set full-year revenue guidance slightly below the current analyst predictions. On the other hand, earnings were said to grow roughly 74% at the midpoint of management's guidance range, which is ahead of the 63% increase Wall Street expected.

In keeping with American Tower's international operations, exchange-rate trends are expected to reduce total revenues by about 3% in 2014. In the second quarter, currency effects reduced core revenue growth by 4%. Any drastic changes to the value of currencies like the Brazilian real, Indian rupee, and Mexican peso could make a significant impact on American Tower's results.