Super Pumped: The Battle for Uber by Mike Isaac:
Kalanick was growing nervous. Across town at Uber’s headquarters, he had heard about Zimride’s plans, and he had heard whispers about Sunil Paul’s escapades, too. Kalanick considered Mark Zuckerberg a friend—or at least a familiar acquaintance—and the Facebook CEO had given Kalanick a heads up. Facebook employees were going crazy for Sidecar, Zuckerberg told him. Zuckerberg warned Kalanick that he might want to keep an eye on the company.
Soon after, Green and Zimmer announced their pivot. Zimride would abandon its long-distance carpooling program and launch a new service called Lyft; the plan was to make casual ride-sharing a fun, friendly experience, asking passengers to ride shotgun next to their drivers and strike up friendships while joyriding to their destination. The cherry on top was a cutesy pink mustache. Lyft sent all of its drivers giant, whimsical, plush hood ornaments to affix to the front of their cars. It was an instant hit.