In the run-up to Nov 11, the country's biggest online shopping day of the year, couriers across China are adding to their transportation fleets and employing "big data" analysis.

The Nov 11 shopping festival, launched by e-commerce giant Alibaba Group Holding Ltd five years ago, has mushroomed into an annual shopping frenzy for millions of online bargain hunters.

More than 20,000 vendors on Alibaba's sites - Tmall and Taobao - have pledged to knock 50 percent off full-priced items on Nov 11.