A big screen shows the online sales for e-commerce giant Alibaba surpassed RMB 100 billion or US14 billion at 01:03:59 after the Nov. 11 Tmall Shopping Festival started midnight in Shanghai, China Monday, Nov. 11, 2019. (Chinatopix Via AP)

Chinese e-commerce giants Alibaba and JD.com reported a total of more than $50 billion in sales on Monday in the first half of Singles Day, an annual marketing event that is the world's busiest online shopping day.

Singles Day began as a joke holiday created by in the 1990s as an alternative to Valentine's Day for people without romantic partners. It falls on Nov. 11 because the date is written with four singles—"11 11."

Alibaba, the world's biggest e-commerce brand by total sales volume, adopted the day as a sales tool a decade ago. Rivals including JD.com and Suning joined in, offering discounts on goods from smartphones to travel packages.

E-commerce has grown rapidly in China due to a lack of traditional retailing networks and government efforts to promote internet use. Alibaba, JD.com, Baidu and other internet giants have expanded into consumer finance, entertainment and offline retailing.

On Monday, online retailers offered discounts on goods from craft beer to TV sets to health care packages.

Alibaba said sales by merchants on its platforms totaled 188.8 billion yuan ($27 billion) between midnight and noon. JD.com, the biggest Chinese online direct retailer, said sales reached 165.8 billion yuan ($23.8 billion) by 9 a.m.

  • In this photo taken Sunday, Nov. 10, 2019, shoppers react as they take part in a promotion ahead of Nov. 11 Singles day in Beijing. Chinese online shoppers hunt bargains on Singles Day, a holiday invented in the 1990s that has become the world's busiest day for online commerce. (AP Photo/Ng Han Guan)

  • In this photo taken Sunday, Nov. 10, 2019, shoppers visit a popular retail district ahead of Nov. 11 Singles day in Beijing. Chinese online shoppers hunt bargains on Singles Day, a holiday invented in the 1990s that has become the world's busiest day for online commerce. (AP Photo/Ng Han Guan)

  • In this photo taken Sunday, Nov. 10, 2019, shoppers react after taking part in a promotion ahead of Nov. 11 Singles day in Beijing. Chinese online shoppers hunt bargains on Singles Day, a holiday invented in the 1990s that has become the world's busiest day for online commerce. (AP Photo/Ng Han Guan)

  • In this photo taken Sunday, Nov. 10, 2019, promoters hand out free gifts as part of a game to promote Nov. 11 Singles day in Beijing. Chinese online shoppers hunt bargains on Singles Day, a holiday invented in the 1990s that has become the world's busiest day for online commerce. (AP Photo/Ng Han Guan)

  • In this photo taken Sunday, Nov. 10, 2019, a child reacts after taking part in a promotion ahead of Nov. 11 Singles day in Beijing. Chinese online shoppers hunt bargains on Singles Day, a holiday invented in the 1990s that has become the world's busiest day for online commerce. (AP Photo/Ng Han Guan)

Electronics retailer Suning said sales passed 1 billion yuan ($160 million) in the first minute after midnight. Dangdang, an online book retailer, said it sold 6.8 million copies in the first hour.

Alibaba kicked off the event with a concert Sunday night by Taylor Swift at a Shanghai stadium.

Chinese online spending is growing faster than retail overall but is weakening as slows and consumers, jittery about Beijing's tariff war with Washington and possible losses, put off big purchases.

Online sales of goods rose 16.8% over a year earlier in the first nine months of 2019 to 5.8 trillion yuan ($825 billion), according to government data. That accounted for 19.5% of total consumer spending. Growth was down from an annual average of about 30% in recent years.