By shortening lead times i.e. the time it takes for clothing to reach the store floor from the designer’s desk, brands like Zara, H&M and Forever 21 for the past couple of decades were nick-named the “fast Fashion”, when Gap and Calvin Klein were the fashion trend setters. Shein further takes this fast fashion trend one step further: Where brands like Zara and H&M take about three to four weeks to bring clothing from the ramp to the store, Shein bring the latest fashion trends to its online store in just a week or two by using a combination of real-time customer and predictive analytics, hyperaware fashion designers and an extremely quick and agile supply chain based in China to from Instagram, Facebook, Reddit and TikTok .