11 November is ‘Bare Branch Day’ in China – a day of celebrations for single people which has become an online discount bonanza. This year, Alibaba, made $9.3 billion of online sales and shipped 238 million packages in 24 hours. Sales hit the $1 billion mark in the first twenty minutes after midnight. 43% of orders were placed from a mobile device.

The phenomenon began in the 1990s with Nanjing University students organising parties on the most single-looking day of the year. Four deep-fried dough sticks (‘youtiao’) and a round stuffed dumpling (baozi) make a popular meal that spells out 11.11. Blind dates have since been introduced and the date has become popular for proposals and even weddings, with the four 1s emphasizing “you are the only one for me.”

“Bare Branches” is a much older term in China for men who are unable to continue the family line. After China’s population doubled in the first 40 years of the Peoples’ Republic, a one child policy was introduced. But the traditional preference for boys has resulted in a massive gender imbalance: by 2020, there may be as many as 30 million more men than women in China.

Alibaba launched its first online discount day in 2009 and registered “Double 11” trademarks in 2012. In this year’s sales, only 2 of the 10 most popular brands were not Chinese: Uniqlo from Japan and Jack & Jones from Denmark.