Allbirds co-founders on their new summertime shoe line
In its first two years, sneaker startup Allbirds sold more than a million pairs of shoes. The San Francisco-based company says it's committed to using sustainable environmental practices to make what it calls "the world's most comfortable shoe." The company is launching Tree, a new line of shoes with material sourced from eucalyptus. Co-founders Tim Brown and Joey Zwillinger join "CBS This Morning" to discuss why they were inspired to start the company and how they developed their new line.