HANGZHOU, China — Singles' Day, a twist on Valentine's Day, started in China in the 1990s as an obscure holiday but has snowballed into a consumer phenomenon thanks largely to Alibaba Group Holding Ltd., founded by Jack Ma and which runs China's largest online marketplace.

Singles' Day is celebrated on Nov. 11 because the date — 11/11 — is reminiscent of "bare branches," the Chinese expression for bachelors and spinsters.

In 2009, Alibaba sparked the flame that turned it into what it is today—a massive marketing event selling everything from electronics and clothing to cosmetics and food at big discounts. It sells through Tmall, AliExpress and Taobao Marketplace platforms, and through merchants' brick-and-mortar stores.

Here are five points that illustrate just how big the phenomenon is:

The sales

Analysts expect sales to surge to a new record. Last year, Alibaba sold more than $1 billion worth of products in the first three minutes of the sales. Total sales on Singles' Day zoomed up to 57.1 billion yuan ($9 billion) within 24 hours, or four times bigger than the US's Cyber Monday, named after the rise in online retail sales the Monday after Thanksgiving. Forty- three percent of transactions were done on mobile devices.

The goods

More than 1 million products were placed on sale last year, according to Comscore. Customers this year will be able to choose from more than 6 million products from around 40,000 merchants and 30,000 brands. Consumers are expected to spend an average of 1,761 yuan ($277) per person, up 22 percent year on year, according to a Nielsen survey of more than 1,000 Chinese Internet users.

The logistics

Alibaba estimates that 1.7 million deliverymen, 400,000 delivery vehicles, 5,000 warehouses and 200 airplanes will be deployed by its partners to handle the deliveries. China Post, the country's postal service, estimates that 760 million packages will be shipped by various Chinese e-shopping sites to customers on the day. That’s up significantly from 540 million packages produced last year, according to a post office quote by Alibaba's news site Alizila. Retailers will be offering more perks such as free refunds and delivery when using online-to- offline channels, according to Bloomberg Intelligence.

The brands

Singles' Day has become more globalized. Alibaba says Costco Wholesale Corp., LG Electronics Inc., Walt Disney Co., Fisher-Price Inc., Lego AS, Metro AG and J Sainsbury PLC will be among the global brands participating this year. Apple Inc., Calvin Klein Inc., Macy's Inc. and Burberry Group PLC have participated in recent years. Major retailers and brands are using Singles' Day as an opportunity to introduce themselves to the Chinese consumer, said Brian Buchwald, chief executive officer of New York-based consumer intelligence company Bomoda.

Offline brands involved in Singles' Day promotions include Shanghai Jahwa United Co. Ltd., Suning Commerce Group Ltd., Intime Retail Group Co. Ltd., Estee Lauder Companies Inc. and BAIC Motor Corp. Ltd., according to a Barclays PLC note on Nov. 4.

The stars

Alibaba is adding some star power to the event, with a guest list that includes U.S. singer Adam Lambert and Chinese film director Feng Xiaogang, known for his top-grossing comedy films. Celebrities from Taiwan and China including pop singer Jolin Tsai, actress Vicki Zhao, Mandopop singers Jane Zhang and Amber Kuo, and boy band TFBOYS were also invited to a Nov. 10 gala ahead of the sales rush, according to a Barclays report.

By Anjali Kapoor, Michael Tighe, Alyssa McDonald.