Pink mustaches. Fist bumps. A seat up front. These quirks help differentiate Lyft as the friendly, human option in an uber-competitive industry. And it's working. Today, the company is one of the fastest-growing ride-sharing apps on the market. We chat with Lyft CMO Kira Wampler about surviving (and thriving) in a competitive industry, scaling non-scalable parts of a company, and hiring the best people for a high-growth team.