How China's most mysterious billion-dollar company won over US teens and became TikTok's most-hyped fashion brand

It's now the largest online-only fashion company in the world, according to Euromonitor. And is redefining fast fashion by cutting production times to one week and adding, on average, nearly 3,000 new styles to its site every week at significantly lower price points than competitors.

This represents a 250% year-on-year increase in revenue. Meanwhile, online rivals Asos' and Boohoo's revenues reached $4.4 billion and $2.4 billion respectively in 2020.

But despite its ubiquitous presence online, the company has a reputation for being very reclusive.

It was set up in 2008 by Chris Xu, whose background is in marketing and search engine optimization. He started out by selling wedding dresses online. In 2012, he diversified into womenswear and later changed the brand name to Shein.

Today, Shein also offers kid's and men's clothing and ships to 220 countries around the world.

"It has changed the way that fashion is produced," Erin Schmidt, senior analyst at Coresight Research, said in a recent telephone conversation with Insider.

This means new products are created in small batches (around 100 items) and production is only ramped up depending on their popularity.

There is less clothing waste because the company doesn't create large quantities of products that customers don't want.

For comparison, speedy UK-based fast-fashion rival Boohoo adds around 500 styles a week.

Xu created a close relationship with his suppliers from the start, according to Schmidt, by doing something that can sometimes seem radical in this part of the world – paying them on time.

In return, factories are required to use Shein's supply-chain management software, which allows the company to closely monitor the manufacturing process and share real-time customer search data with suppliers to guide design and production.

Source: Bloomberg

They must also be able to complete the design and production process in as little as 10 days.

This is substantially faster than its competitors, especially legacy brick-and-mortar rivals such as Zara that typically have a five-week turnaround time.

Prices start from under $1 for accessories and you can easily snap up a dress or sweater for under $10.

Such videos are widely shared on social media and illustrate how many items you can buy for $100, for example. This is free marketing for the brand and a key reason why it's become so successful on social media.

It has 21.4 million followers on Instagram and 2.4 million on TikTok.

This year, it caused controversy for selling a necklace with a swastika charm, which it later said was meant to represent a Buddhist symbol, rather than a Nazi swastika.

It was also called out for listing Muslim prayer mats on its site, which were advertised as "decorative rugs." Shein apologised via a statement posted on Instagram. It also removed the prayer mat items from its site.