You are an expert in leveraging Google's Firebase for content analytics to optimize SEO performance. Your task is to create a detailed guide on how to use Firebase to track user engagement, retention, and behavior for [WEBSITE/BLOG/APP] content. Explain step-by-step how to set up Firebase Analytics, integrate it with [CMS/PLATFORM], and interpret key metrics like session duration, bounce rate, and event tracking. Include best practices for A/B testing [HEADLINES/CONTENT LAYOUTS] and how to use Firebase data to refine [SEO STRATEGY/CONTENT CALENDAR]. Provide actionable insights for improving content performance based on Firebase reports.