How do you communicate in just 8 second that a viewer should continue to read or watch your content? You need to show that your content is relevant to your viewer and that it has value to them.
Then you need to give them an easy path for further engagement with your content. Sounds like a tall order, I know, but this infographic from SDL breaks down the tasks into manageable sub-categories.
Via Ivo Nový, massimo facchinetti