T-Mobile’s VP of media Kari Marshall explains why marketing in the telecommunications space is like Game of Thrones, how the company went from being nearly bought by another company to becoming the second-largest wireless carrier in the U.S. after acquiring Sprint, and why the brand has its own in-house agency.

REI’s Vivienne Long on purpose-driven marketing

The Big Impression returns for another season of insights and inspiration from leaders at the world’s most influential brands. Editors and co-hosts Damian Fowler and Ilyse Liffreing will look to uncover candid stories on game-changing campaigns from some of the world's biggest brands — including wins, losses, and lessons. New episodes are released every Wednesday.