Happy Singles Day!

What's that? It's a sort of anti-Valentine's Day, believed to date back to at least 1993, when students at China's Nanjing University decided to celebrate single people by buying themselves things, according to Tech In Asia. It didn't really become a major online shopping day until 2009, when Chinese e-commerce giant Alibaba started doing big sales on the holiday, although the company has distanced itself slightly from the loneliness angle by trademarking the term "Double-Eleven" for the sale date and protecting it vigorously.

Since then, Nov. 11 has ballooned to be the largest online shopping day in the world.

Last year, Alibaba platforms sold $5.7 billion worth of goods on the holiday, an 83 percent jump from the year before. This year Alibaba says they sold more than $1 billion worth of goods within the first 20 minutes of the sale. By midnight Beijing time, sales had climbed to more than $9 billion.

In 2013, popular U.S. online shopping days Cyber Monday and Black Friday combined didn't come even close to that amount of e-commerce -- bringing in just $3.5 billion between them via desktop and mobile shopping, according to comScore.

While just around 20 percent of Cyber Monday and Black Friday sales came through mobile last year, over 40 percent of Alibaba Singles Day purchases were mobile sales, reflecting how the rise in Chinese online connectivity has been fueled by a bump in mobile users.

E-commerce is still playing catch-up with brick-and-mortar shopping holidays. Last year, Black Friday weekend customers bought $57.4 billion worth of goods in the United States, according to the National Retail Federation.

But Alibaba founder Jack Ma has grand plans for Double-Eleven. "'I wish it will be a global shopping day for United States, Europe, anywhere in the world," Ma said during a CNBC interview, suggesting the 11/11 shopping bonanza will go global within five years.