"We called them maidservant clothes and butlers' clothes because we want to stress their purpose is to serve customers," Zhang added.

Apart from the themed flights, Wang is also considering launching in-flight car sales during Spring Airlines flights.

"I started to dream of selling cars on planes ever since the establishment of Spring Airlines," said Wang, adding that the decision is made based upon their own special conditions.

There is more free time for flight attendants on Spring Airlines because they do not have to serve every passenger with drinks and food during flights. They therefore have time to advertise goods.

According to Wang, 80 percent of the company's more than 10 million passengers per year book tickets online. They tend to be white-collar workers at the stage of buying their first car or home.

"These are the foundations for in-flight car sales," added Wang.

Wang said he has more dreams to realize. "I have always wanted to launch flights between Shanghai and Taipei. The current ticket price between the two cities is even more expensive than the combined ticket price of traveling from Shanghai to Hong Kong and from Hong Kong to Shanghai," Wang said.

But, unfortunately for Spring Airlines, the company's application to begin flights to Taiwan has been rejected every year by the Civil Aviation Administration of China for reasons known only to itself.

"We started to apply every year since 2007 but never received approval. Some people suggested it's because our prices are too low. But isn't that our responsibility to let more people afford trips by air?" said a sighing Wang as he wore a confused and helpless expression.

However, another dream may come true for him: taking the company public. Spring Airlines is now lining up for approval from the China Securities Regulatory Commission to undergo an initial public offering on the Shanghai stock exchange. If successful, Spring Airlines will become the only listed private airline on a China mainland bourse.

It has been years since the budget carrier sought an IPO in the A-share market. In late 2006, Citigroup proposed Spring Airlines' listing, estimating its market capitalization at 8 billion yuan. However, the global economic meltdown in late 2008 and ensuing capital market collapse halted the effort.

"I love to work here very much not only because Spring Airlines is a successful company and has never lost a penny throughout its life, but also because this is a workplace with open-minded people," said Jonathan Hutt, deputy general manager of strategy and international brand director at Spring Airlines, who has worked there for three years.

"People here can really learn stuff in this challenging place. This company is destined to have a great future," he added.

Zhang Xiaoxian in Shanghai contributed to this story.