Reuters
The holiday is called Singles' Day and it's held every year on November 11. It's like China's version of Cyber Monday, but seven times as big.
Alibaba - China's largest e-commerce company - has helped turn Singles' Day into the biggest shopping frenzy in the world by offering deep discounts during the 24-hour period on items as varied as cars and clothes.
Hundreds of other companies have started taking part in the cyberspending blitz over the years by offering discounts of their own.
So why don't more Americans' participate in Singles' Day - or even know what it is?
US retailers are largely to blame, as most of them have been reluctant to add another "Black Friday" or "Cyber Monday" to their fall calendars.
"All retailers are laser-focused on ramping up for the period from Black Friday to Christmas," says Danny Silverman, head of product strategy at ecommerce analytics firm Clavis Insight. "To participate in Singles' Day would sap sales from that critical period."
Reuters
Singles' Day also coincides with Veterans Day in the US, and some retailers already plan promotions tied to that holiday, says Tom Caporaso, CEO of Cla
Several US-based companies do in fact participate in Singles' Day - including Walmart, Macy's, Gap, Target, and Costco - but very few of them offer deals to domestic shoppers.
Most of them target Chinese shoppers on Alibaba's shopping websites Tmall and Taobao.
In fact, Costco was the top TMall Global seller on Singles' Day last year. The company sold about $3.14 million worth of products in a single hour, according to Alibaba.
The most popular brands sold on Singles' Day last year include Uniqlo, Nike, Adidas, and New Balance.
Reuters
By comparison, Americans spent $5.8 billion online last year on Black Friday and Cyber Monday combined, the largest sales days in the US.
Caporaso says its only a matter of time before more US retailers take advantage of Singles' Day and start promoting it domestically.
"Last year, QVC, Michael Kors, and Bloomingdale's offered specific promotions, and we expect a similar showing this year, with additional retailers potentially joining the festivities as Singles' Day approaches," Caporaso says.
So US shoppers should keep their eyes peeled on Singles' Day, because there might be some unexpected deals coming their way.