The difference is in the way they do logistics and on-demand/just-in-time production. Shein is deeply integrated with its suppliers - H&M and similar are not.

The difference is in the way they do logistics and on-demand/just-in-time production. Shein is deeply integrated with its suppliers - H&M and similar are not. Traditional retail - like H&M - has a markup of around factor 10 (meaning if something is 100 in the store, the factory/shipping company gets 10) - and supplier lead times of 3-6 months. Shein has much lower markup and lead times of down to under a day.