Purpose of letter/s is to read and act.Purpose of word/s is to respond. Purpose of feature.film/s is to view and talk. Purpose of book/s is to study and analyse. Purpose of discussion-meeting/s is to deliberate and hear. Purpose of YouTube video/s is to broadcast and analyse.

Any letter/s or word/s or feature film/s or book/s or discussion-meeting/s or video/s must serve its intended purpose.
Suppose I tell you "You give tea and I give you its price".
That means either you have to give tea or you have to say about it.
Otherwise it is meaningless to tell.