SHANGHAI (Reuters) - Black Friday? No. Cyber Monday? Nope. Prime Day? Absolutely not. The world's biggest shopping event happens in China each year - and it's called Singles Day.

Originally a holiday to celebrate being single, as a counter to Valentine's Day, the event has grown into a weeks-long online shopping festival that this year began on Oct. 14 and peaked on Nov. 11 - making it the longest Singles Day sales period ever.

WHEN DID THE IDEA OF SINGLES DAY ORIGINATE?

The idea for Singles Day had originated at China's Nanjing University back in 1993 and was originally called "Bachelor's Day." On the day, single people treat themselves with gifts and presents, while also organising social gatherings and parties.

HOW MUCH DO CONSUMERS SPEND?

Last year, the total value of goods sold during the shopping bonanza - also known as "Double 11" - totaled 1.14 trillion yuan ($156.4 billion), according to data provider Syntun.

That is more than four times the $38 billion U.S. shoppers spent last year during Cyber Week, the period from Black Friday to Cyber Monday, per data from Adobe Analytics.

Cyber Monday immediately follows Black Friday, which falls on the day after the U.S. Thanksgiving Day holiday, the busiest shopping day of the year in the United States.

But growth has been slowing even as overall sales for Singles Day hit record highs, with last year's 2% rise marking the slowest increase ever.

The event has in recent years lost some of its novelty with the rise of other shopping festivals in China, including the midyear "618" sales that are the country's second-largest and this year saw overall sales fall for the first time.

"Vendors are becoming more rational, gross merchandise value is not the core pursuit, profit is," said Lu Zhengwang, an independent e-commerce expert. "However, profit is hard to reach, the competition is still super intense, and only the cheaper price sells."

WHAT MAJOR BRANDS AND PRODUCTS ARE SHOPPERS BUYING?

While Alibaba ( BABA ) started "Double 11" in 2009 to win over online shoppers with discounts and promotions, China's major e-commerce platforms now all take part in it.

JD.com ( JD ) joined in 2012 and PDD Holdings ( PDD )-owned Pinduoduo has also become a significant player, offering low cost products in competition with Alibaba ( BABA )-owned Tmall and Taobao platforms.

Last year, shoppers spent on necessities such as tissues, handwash, instant noodles and pet food, while trading down and buying less in discretionary or big-ticket categories such as home appliances and furniture.

This year, household appliances are likely to perform better than last year, benefiting from a national 150 billion yuan trade-in subsidy scheme announced in July to help boost consumption.

According to a Bain survey conducted before the beginning of the Singles Day sales festivals in late October, 49% of Chinese shoppers said they were excited by the event, down from 53% in 2023 and 76% in 2021.

About three-quarters of respondents said they would spend the same amount or less on Singles Day promotions in 2024.

HOW DOES SINGLES DAY COMPARE TO BLACK FRIDAY?

U.S. shoppers last year bought smart watches, toys and video games during the key Black Friday and Cyber Monday shopping periods, according to Adobe.

From 2014 until 2021, Singles Day had posted growth rates of about 34% annually on average, versus Cyber Week's 17% average gain, according to data from consultancy Bain and from Adobe Analytics.

WHAT OTHER COMPANIES HOPE TO BENEFIT?

Several American companies from apparel maker Nike to cosmetics firm Estee Lauder and consumer goods giant Procter & Gamble have a big presence on Chinese e-commerce platforms such as Tmall and JD.com ( JD ).

Aggressive discounting has been a hallmark of Chinese shopping festivals, especially since the end of the country's harsh COVID-19 restrictions in late 2022 with low prices leveraged to manufacture a consumption comeback that hasn't really eventuated.

This year, platforms offered low prices on Apple ( AAPL ) iPhone 16 models, with Tmall offering as much as 1,600 yuan off the phone with subsidies applied. JD.com ( JD ) discounts were similar and also included a free year of AppleCare+.

L'Oreal CEO Nicolas Hieronimus on a post-earnings call with analysts in October said it was too soon to comment on "Double 11."

"The length - the duration of 11.11 has been extended. It's going to be the longest 11.11 ever, has been increased by 10 days," Hieronimus said. "We are determined to have our brands in the top rankings of this event."