The reasons vary, from environmental and sustainability factors to dramatically lower prices for name-brand items. There’s also a thrill of the hunt aspect to shopping in secondhand clothing stores. Buying used clothes is far from a new phenomenon. A certain segment of every new generation of teens and 20-somethings invariably gets drawn into spending time combing through the racks at thrift shops or flea markets. But in the last decade, the emergence of online, peer-to-peer fashion resale marketplaces has turned the act of purchasing and selling used clothes into a much more mainstream activity.