PLAIN-LANGUAGE DEFINITION
Hook
A hook is the opening idea intended to make the right viewer keep watching.
IN PRACTICE
An example
A bag video can open with the question of whether a specific laptop fits.
What this does not tell you
Attention alone is not enough if the rest of the video does not answer the opening.
Use the term precisely
When you use this term in a brief or report, include the relevant source, scope and assumptions. An example explains the concept; it is not a benchmark or a promise of results.