12306.cn, China's official website for purchasingrailway tickets, has become the largest of this kind inthe world, with combined sales reaching 3.5 billion in2017.
"If all these train tickets were lined up, they wouldcircle the earth 7 times," said Zhu Jiansheng, deputy director of the Institute of ComputingTechnologies with the Chinese Academy of RailwaySciences, where the ticketing system was developed.
Since its launch in 2010, the 12306 ticketing system has been upgraded many times to fix bugsand provide better service during the Spring Festival travel rush, or Chunyun.
The system sold around 1.1 million tickets during the 2012 Spring Festival travel rush. Lastyear it sold 11 million over the same period.
Around 280 million train tickets have been sold on 12306.cn since Jan 3, 2018 when tickets forthe Spring Festival holiday started selling.
The sales volume peaks at around 15 million per day, with nearly 700 tickets sold in everysecond.