Anticipating a hit movie

I was discussing 'hit movies' with a friend and he mentioned that a movie is release on Friday and in Saturday newspapers we can see ads and articles mentioning movie's earnings and halls being houseful. The ad copy and design should be prepared well in advance in order to make it in newspapers on first Saturday. Or am I wrong in thinking that?

Are movie producers and newspapers flexible and agile (and should I say efficient) enough to calculate or estimate earnings on Friday and declare the movie as a winner or it's an attempt to fool the crowd to watch the movie 'once' because it seems to be a 'hit movie'?