Fewer brick-and-mortar facilities may make Chinese firms more nimble, but maintaining a large labor force can be a challenge when it comes to expanding into other countries that pay their workers more. Within China, labor costs could also rise, as employees demand more money given the manual nature of the work and air pollution, Rein said.
Other aspects of the domestic Chinese market make it very competitive. More than 11,000 enterprises had authorization to operate express delivery businesses as of the end of 2014, according to a Deloitte study last year. About 60 to 70 percent of the Chinese market was spread among the top 10 players, including the state-backed delivery firm EMS. That compares with the dominance of just two companies — UPS and FedEx — in the United States.
However, the desire to grow beyond China is there.
"We plan to expand our global footprint. We plan to start with the U.S. marketplace," ZTO's chief financial officer, James Guo, told CNBC in a phone interview last week.
Guo said ZTO recently entered into a partnership with the United States Postal Service for cross-border transactions. However, a USPS spokesman said he could not confirm the existence of any partnership with ZTO and would not comment on USPS operations in China.
ZTO did not respond to a CNBC request for a follow-up on the status of any deal with the USPS.
In any case, as cross-border transactions are only about 1 percent of ZTO's business, Guo said the company will focus for now on China. The firm holds about 14.5 percent of Chinese market share by parcel volume, according to its prospectus.
Whether helped by favorable protectionist policies or pure competitive edge at home, Chinese delivery companies may one day be established enough to grow significantly outside their home market.
"The revenue base is going to be able to fund (operations) in markets where they think they'll be competitive" such as Africa or South America, said Derek Scissors, chief economist at China Beige Book International, which regularly surveys Chinese businesses.
In addition, "rather than establish a new brand in a very competitive market," he said, a Chinese company "can buy a brand and keep it" as theirs.