The world’s biggest shopping day is happening right now, and you probably don’t even know it.

In China, it's already November 11, or 11/11, and the massive e-commerce event known as “Singles Day” is well under way. Launched by Chinese e-commerce giant Alibaba in 2009, the idea is that for a full 24 hours, shoppers who are unmarried and unattached should go online and splurge on a nice gift for themselves.

How big a deal is Singles Day? This year, during Alibaba’s four-hour television event the night ahead of Singles Day (yes, this year they celebrated “Singles Day’s Eve”), Alibaba trotted out a parade of Chinese pop celebrities and movie stars. James Bond (er, Daniel Craig) appeared onstage with Alibaba Executive Chairman Jack Ma. Kevin Spacey made an appearance via video in his House of Cards persona, President Frank Underwood.

In short, no expense was spared in the bonanza. And no expense will be spared in Alibaba’s execution of the event, either. This year, Alibaba moved the opening gala from the company’s Hangzhou headquarters in eastern China to Beijing—the capital of China, where its biggest rival, e-commerce platform JD.com, is based. Despite losing $55 billion in US market value this year, and in spite of a slowing economy in China overall, Alibaba says it still plans to deploy 1.7 million delivery personnel, 400,000 vehicles, 5,000 warehouses, and 200 airplanes to take care of package deliveries.

“When Singles Day becomes a national shopping celebration, competitors might enjoy the same or stronger growth in that day, too," Jane Zhang, a principal research analyst for market research firm Gartner, who is based in China, tells WIRED. "So in a sense, the sales of the Singles Day does indicate the growth momentum of Alibaba and its competitors."

At least judging by the initial numbers, the company’s efforts have paid off. In the first 90 minutes after the Singles Day kickoff, at midnight in Beijing, Alibaba said it surpassed $5 billion in total sales. Seventy-four percent of those were from mobile phones. And international brands—from Nike to Apple—often offer discounts to lure more buyers.

Last year, Alibaba’s total sales hit 57.1 billion yuan, or $9.34 billion, on 278 million shipped orders. Meanwhile, in the same year in the US, online sales on Black Friday promotions—that is, Thanksgiving through Cyber Monday—amounted to just $6.56 billion, according to research firm eMarketer. Note that figure spans all online US retail companies, compared to the payload for just one Chinese company, Alibaba.

We have yet to tally how much Alibaba makes on Singles Day this year, but Bloomberg says total sales could reach 87 billion yuan, or $13.7 billion, citing research from market research firm IDC. That’s huge, but not overly surprising, considering China’s per capita disposable income rose 7.7 percent in the first nine months from a year earlier (also according to Bloomberg), outpacing a 6.9 percent rise in gross domestic product. A recent survey from Nielsen, meanwhile, found that 56 percent of consumers said they would spend more on Singles Day this year than in 2014, and overall awareness about the online shopping holiday among Internet users had risen this year compared to last as well.

It's likely that future Singles Day events will be even more enormous, given that there's still so much runway for e-commerce growth in China. "Consumer behavior is quickly changing and many [Chinese] consumers are yet to become active online shoppers," says Sandy Shen, a research director with the e-commerce team at Gartner. "Online retail sales will see double-digit growth for the next 5 years."

So, yes, Singles Day is a certifiable hit, even as most of us in the US sit here, completely unaware it’s going on. But the impact of this clever made-up holiday isn’t just limited to overseas. You can bet that every retailer is watching in hopes of grabbing even a tiny piece of that success.

Update (November 11, 2015, 1 pm ET): Reuters is reporting that the total value transacted by Alibaba this year is $14.32 billion (though that number hasn’t been audited yet). This exceeds analyst estimates. It's also up 60 percent for Alibaba from a year ago. Alibaba says it surpassed its total sales orders from last year—57.1 billion yuan, or $9.34 billion—by noon. Sixty-eight percent of the total value of transactions came via sales on mobile devices, the company said.