YouTube Trend Manager, Kevin Allocca, offers insights to why some videos made it top on the viral list.
From a web writer’s standpoint, I would also add that SEO plays a huge role in propagating high traffic videos. Notice how this post is entitled; some words are used for certain reasons. Time to spill the bean. Many bloggers & SEO writers include viral videos in their posts so to increase the visibility of their entries and improve search-ability on Google or other search engines. Long story short, it is a self-fulfilling and self-regenerating chain effect. The more the people like it, the more publicists would use it.