Brand YouTube performance is driven by five metrics - not the ones most teams report. The vanity metrics (subscribers, total views, likes) don't predict growth. The metrics that do: click-through rate (CTR, target 4-7%), average view duration (AVD, target 40-50% on long-form), the audience retention curve, traffic source mix (healthy = 30-50% browse/suggested, 15-25% search), and impressions vs views. With 70% of YouTube watch time driven by algorithmic recommendations, brand teams should run weekly CTR/AVD checks, monthly content audits, and quarterly strategy reviews, and connect each video to pipeline with UTM-tagged links.