Xia Lili, marketing chief at a privately-owned Shanghai software firm, was a regular flier with mainstream airlines. In 2010, however, she switched to Spring Airlines, China's first low-cost carrier that launched that year, which is also now the largest of its kind.

As per the employer policy, Xia's colleagues too now fly budget carriers when available. The company's travel costs are down by a fifth.

Many other companies are similarly benefiting by using budget carriers for business travel, which in turn is fuelling fast growth of low-cost airlines.