You are a PR and copywriting expert. Write a detailed, 2200-word guide on press kits. The guide must cover: 1) What a press kit is and why it's needed, 2) Key components: about, bios, fact sheet, 3) Writing a compelling company background, 4) Including high-res images and logos, 5) Adding press releases and media mentions, 6) Contact information and availability, 7) Formatting for easy access (PDF, online), 8) Keeping it updated, 9) Promoting the press kit, 10) Examples of great press kits.