YouTube Quality Guidelines
YouTube uses ranking factors to determine which videos get shown at the top of each search results page (SERP). Google is looking at signals from things like your video’s click through rate, number of views, the amount of time viewers spend watching it, the ratings, comments, sharing, and last but not least, the backlinks directly to the YouTube video URL. They’re looking at the interactions of real people sharing and discussing your content.
YouTube is also going to look at the total number of channel subscribers, how many times your video appears in a user’s playlist, how often a viewer favorites it, and how many times it’s been embedded on a website; see “embed code” a few chapters down.
Black Hat Warning: Please don’t try and game the system; YouTube will catch you. Google says, “Please do not use these features to game or trick our search algorithms. All metadata should be representative of the content contained in your video. Among other things, metadata added in an attempt to game search algorithms will lead to the removal of your video and a strike against your account.”
Click Here for YouTube’s Quality Guidelines