China's online retailers are cashing in on Singles' Day, a holiday that celebrates young single Chinese every November 11 and is quickly becoming the biggest e-commerce sales day in the world.

Tmall, Alibaba's business-to-consumer (B2C) platform, saw its trade volume spike to 10 billion yuan ($1.6 billion) as of 1:38 pm on Sunday, according to official data released by the company.

The holiday has even outpaced Cyber Monday in the US, the day after Thanksgiving weekend and online Christmas shopping begins, where trade volume reached $1.25 billion last year, according to statistics released by US-based research firm comScore.

First made popular in the 1990s to celebrate unhitched students at universities, Alibaba's retail arm began promoting Singles' Day sales in 2010, according to the Xinhua News Agency.

Only two years later, around 77.5 percent of B2C dealers are offering "50-percent off", "gifts" and "bonuses" for Single's Day sales events, according to a report by the China E-Business Research Center Wednesday.

The flood of promotions has triggered nationwide discussion over the reasons why online shopping dominates Single's Day and the challenges B2C merchants face in meeting demand. 

@王冉：Promotions on Singles' Day do not necessarily mean good things for e-commerce. Artificially creating a consumer rush could pose a great challenge to B2C inventories, shipping and customer service. Meanwhile, it might reinforce a bad habit among Chinese consumers to judge goods only in terms of its price, while leading B2C companies to only pay attention to the prices of their products and not quality. 

@于清教: The targeted consumer demographic on Singles' Day is actually quite limited. These large-scale sales campaigns also illustrate the predicament of China's e-commerce dealers.

We should place more importance on product quality, management and the market instead of promotions or moving overstocked products in the shadows of a lagging economy.

@谢谦-奥义: The reason behind the popularity of these Singles' Day sales is because young people celebrate Singles' Day, and they make up the strongest online consumer demographic. Also, Singles' Day does not fall on an official holiday, so shipping companies and merchants are better able to cope with the huge amount of traffic and trade. B2C companies also take the chance to launch clearance sales at the end of the year to boost numbers on their annual financial reports. Furthermore, young people usually like to make plans at the beginning of a year for major purchases at the years' end. They are more than happy to find the things they've planned to buy at discounted price.

@陆乾宇：Some consumers stay up all night comparing prices on different B2C sites, only to find that they can't process their purchases because the system is bogged down with so much traffic.  

@无厘头小泽：The recent bonanza on Singles' Day is actually driven by the sellers. Personally I don't pay attention of any of their sales, nor do I need to complain about the swamped payment platform. I place more importance on the quality of goods and I only buy from real stores. Besides buying new clothes on New Year's Eve, I keep my purse strings pretty tight.