On May 17, Shein surpassed Amazon as the most downloaded iPhone shopping app in the US, something it had already done in Google Play downloads the week prior, according to analytics firm App Annie. The online-only retailer was formed in Nanjung, China, but ships its products, primarily inexpensive women’s apparel, to more than 220 countries worldwide. Researchers and consumers site innovative digital strategies and low-priced, trendy products that appeal to a Gen-Z mindset as key to the retailer’s success.