YouTube SEO
YouTube SEO optimizes videos for the platform’s internal search engine (the world’s second-largest search engine) and for Google Video results, by working on title, description, tags, chapters, transcription, and thumbnail click-through rate.
In practice
YouTube weighs audience retention heavily: a video watched to 70% on average will be favored over one watched to 30%, even if the latter has more total views. Chapters (timestamps in the description) improve retention and trigger mini-snippets in the Google SERP for each section. The auto-generated transcript, corrected manually, improves indexation of spoken keywords.