The extension estimates the "true" dislike count based on the like/dislikes it has in its database. E.g. if the database contains 100 dislikes and 900 likes, bu

The extension estimates the "true" dislike count based on the like/dislikes it has in its database. E.g. if the database contains 100 dislikes and 900 likes, but the video has a million views, it'll estimate 1000 dislikes. I'm sure there's some cleverness in there for videos where it doesn't have a tonne of information yet.