The carrier's average load factor in 2012 was 95 percent, while the load factor of the whole industry was more than 80 percent.

At the very beginning, about 80 percent of passengers of the carrier were tour groups from its parent company, Shanghai Spring International Travel Service Ltd, but the percentage has fallen to no more than 15 percent, Wang said.

After developing over the years, Spring Airlines also has its own stable group of customers.

"As many as 75 percent of our ticket-buyers are from the younger age group below 30 years of age," said Zhang Wu'an, spokesman for Spring Airlines.

In order to lure young customers, Spring Airlines is active on social media Internet sites and uses innovative marketing techniques, such as blind-date flights.

The young passengers are used to buying tickets through mobile terminals and official websites, which encourages the carrier to add more direct sales, Zhang said. It is also a cost-saving practice.

China's increasing individualized tourism provides passenger flows to the budget airlines, as well.

China's inbound tourism number was almost 3 billion person-trips in 2012. No more than 5 percent of them were part of tour groups, according to a Chinese tourism report on vacations booked personally released by China Tourism Academy.

"The percentage of such travelers in China is already close to that of developed countries," said He Yong, deputy general manager of Ctrip International's tourism department.

The price of air tickets from Spring Airlines is usually 42 to 45 percent lower than the average price on the market. It is attractive for travelers with limited budgets who want to determine the scope of their holiday personally.

The carrier is well-known for its series of tickets priced 9, 99 and 199 yuan respectively. It provides 20 to 30 percent of the tickets with special discounts on every flight, Zhang said.

"Although we provide many discounts, Spring Airlines still manages to maintain a profit through saving costs and increasing income," he said, without specifying details.