Tim Brown, co-founder and co-CEO of Allbirds, discusses why only bad retail—not all retail—is dying, how he navigates the unique position of having two chief executives at his company, and Allbirds' quest to achieve what has never been done before: run a billion-dollar business without leaving any carbon footprint behind. "One of the challenges with a topic like sustainability is that it means 10 different things to 10 different people," he says. "Where we've landed as a business is that they must all ladder up to this unifying metric around carbon. Carbon is the thing that we must get under control." Brought to you by Shopify Plus, the enterprise platform powering brands from Allbirds and Gymshark to Staples and Heinz. Join the revolution at shopify.com/plus.