There Have Only Been 21 Movies That Have Ever Gotten "F" Ratings From CinemaScore — How Many Have You Seen?
Justice for "I Know Who Killed Me."
CinemaScore is a market research company that polls audiences on opening night and gives movies grades based on those scores. Here's how they describe themselves:
Since 1978, CinemaScore has been polling moviegoers at major movie releases on opening night to collect demographic information and calculate a distinctive CinemaScore grade.