Why are some film called "blockbuster"?

    "Blockbuster" is a term generally used in the entertainment field. Blockbuster films are film that achieve huge commercial success. The term "blockbuster", is  a combination of two words, "block", and "buster". It originated in the 1940s in american press, and denoted a huge aerial bomb capable of destroying a whole block of street. Later, this term was used for referring to anything making a significant public impact. The  entertainment industry adapted this term easily, and it is used for successful films, plays and novels, etc...

   in 1975, Steven Spielberg's "jaws", was released. It became a box office hit, and is considered as the first blockbuster film coming under the hollywood's new blockbuster genre....