For
It keeps mystery and excitement alive.
Against
Viewers want to know what they are paying for.
Anonymous excerpts, translated where noted.
“But most trailers are purposely misleading by design.”
“Watching it again, I enjoyed it much more without comparing it to the movie my brain wrote after seeing the trailer.”
“Trailer are designed to get you interested in the product.”
“If a trailer or actor appeals to me enough, that's all it'll take for me to see it.”