Punctuation's classical use is to support syntax; it has a secondary use to support "sounding aloud" breath control: comma, small pause. period full stop.
Take your example:
"...the critic quote on the front reads: Best. Vampire. Movie. Ever."
Read aloud "The best vampire movie, ever." has little audible punch. We can add punch, increasingly with'
"The best vampire movie, ever!"
"The best vampire movie. Ever!
"The best vampire movie!" Ever!
leading us to:
"Best. Vampire. Movie. Ever." (Each word spoken as a heavily stressed one-word sentence)
Those of us who have our own personal anal-retentive pixie who reads aloud in our inner-mind while we silently read from the page appreciate the technique.
Some of my favorite prose works (Baldwin's "Giovanni's Room", Conrad's "Heart of Darkness") sound like poetry when the pixie is speaking.
der Brucer
Lesson Two is is the use of language to invoke imagery which then conveys meaning (examples, T.S. Eliot, Walt Whitman, L. Ferlinghetti ).