After revolutionizing the airline industry, serial entrepreneur David Neeleman has his sights set even higher: He's intent on radically changing the entire country of Brazil with a startup airline that's bringing air travel to the masses. And it all started with a stroller.

Neeleman, who previously founded Morris Air and Jet Blue, was walking the streets of Brazil, wondering why parents didn’t have strollers. The reason was simple: They couldn't afford them, because strollers cost four times as much in Brazil as they did in the U.S. There wasn't anybody catering to the country's burgeoning consumer class. It dawned on him that it was the same story with air travel.

Brazil had only 50 million enplanements, compared to 750 million in the U.S. Brazilians were flying less often than Mexicans, Chileans or Argentines. Rail travel was nonexistent, and bus service was expensive. Neeleman saw a massively underserved market and jumped in.

Fast forward four years: Azul now owns 70 percent of the market in the cities it serves, and has no competition whatsoever for 55 percent of its flights. Campinas, an airport in the exurbs of Sao Paulo, now carries an additional 600 people per day to and from the Bahian city of Savlador, and another 1,800 daily to Rio. Passengers include not only business travelers but even domestic help returning to their hometowns in the countryside over a long weekend, a journey that once took 27 hours by bus. By creating competition, Azul has forced Brazil's legacy carriers to reduce prices, allowing an additional 40 million Brazilians to take to the skies.

As it was at his two previous startups, Neeleman's primary focus is on the customer experience. That's why his planes have leather seats and no middle seats. Neeleman also insisted he doesn't pay attention to shareholders, a lesson he learned from Southwest chairman Herb Kelleher. If you take care of your customers, he said, they will take care of the shareholders.