Poshmark CEO and founder Manish Chandra told Cheddar it seems unreal to think that 10 years after starting the secondhand fashion app he'd be competing with retailer Urban Outfitters, which recently announced its own used clothing platform. But, he said, consumer demand for sustainability has significantly changed the landscape that was once dominated by fast fashion. "What you see in Poshmark is millions of closets networked together really crafting the future of shopping, and we think the future of shopping is simple, it's social, and it's really sustainable."