Generate a full, in-depth guide for business owners on how to build a powerful brand community. The guide must be written in a strategic and engaging tone. It must include detailed sections on: 1. The 'Why': The psychological drivers of community and its impact on customer lifetime value. 2. Platform Selection: A detailed comparison of platforms like Facebook Groups, Discord, and dedicated forums. 3. Content & Engagement Strategy: Provide a list of at least 10 specific content ideas (e.g., member spotlights, weekly challenges). 4. Moderation and Culture-Setting: A guide to creating community guidelines and managing conflict. 5. Measuring Community Health: A breakdown of key metrics to track. Please include a disclaimer that community building is a long-term investment.