A car owner in his expensive Jaguar.

"During rush hours the subway is overcrowded, and carpooling is an affordable and convenient way of getting to and from work, especially for youngsters. Some of my young single employees are even looking it as a new way of finding a boyfriend or girlfriend."

For those who use the carpooling apps, the usual conversation ice-breaker will relate to what kind of work each of the parties does, so some apps have broadened to become a platform for talking about careers and even job opportunities and offers.

Zhu, a consultant for overseas study tour programs for adults, says such programs are relatively new in China, and some of the car owners who have driven her have shown a keen interest in the topic.

"This is not set up. Random chats just occur. People are interested in what you do and you simply talk about it with them. I once met this guy who had opened a cafe, and he told me all kinds of things about coffee."

Zheng Yi, 27, executive director of an Internet company in Shanghai, says that often when he is carpooling he bumps into people from his industry because his company is located in an area where many startup companies are located. They have learned a lot from one another during such encounters, he says.

"It's possible to dig around by using carpooling or car-hailing apps. The first passenger I met told me he was looking for new opportunities and came to our company for a chat later."

Some of Zheng's colleagues distribute brochures of their products when they use such apps.

"It's much better than dishing out fliers randomly on the street because some drivers are our target customers, those interested in starting their own business."

Duan Yan, 32, an office worker from Beijing, says she has carpooled with others more than 120 times. She sits in front of a computer all day, she says, and carpooling has become an important tool that helps her socialize.

"It's an environment in which people can chat, and most are willing to talk. I get to pick up a bit of basic knowledge and inside secrets on the fields they work in, and some proffer career advice."