Channel 4's mission is to bring niche and controversial subjects to mass audiences, as seen in shows like Benefits Street that sparked political debates. They aim to support lesser known stories and filmmakers. Channel 4 harnesses social media by uploading TV ads and full episodes to YouTube and Facebook to encourage discussion. The document suggests editing a campaign to mimic Channel 4 by creating sensationalism or controversy in promotional materials to encourage sharing, and setting up social media discussions to increase hype for a production.