Reinhart: thredUP’s signature polka-dotted Clean Out Kit was our first innovation and remains one of our most important ones to this day. It holds up to 30 pounds of apparel, shoes, and accessories, ...

ThredUP sends sellers a "clean out kit," and customers fill up the hamper-sized bag with the clothes they want to sell. The bag is pre-addressed and includes postage. All customers have to do is ...