This document discusses Twitter and its evolution as a central part of the digital ecosystem. It provides examples of how Twitter was used to spread real-time information about a helicopter crash in London and how brands like Adidas, Four Seasons hotels, and Vodafone Australia have used Twitter to engage with customers, resolve issues, launch marketing campaigns, and improve their brand image. The document also shares statistics on Twitter's growth and how the platform is increasingly being used to discuss television shows and drive other online interactions.