1. A method of analyzing videos, said method comprising: a) providing a digital database comprising a plurality of digital video files; b) selecting one of said digital video files for analysis; c) if necessary, transforming said one of said digital video files into a selected format comprising sequences of frames or photograms and audio files; d) processing said one of said digital video files to extract video descriptors and metadata; e) processing said one of said digital video files to establish correlations among said video descriptors; f) establishing an output measure that relates said video descriptors with audience data; and g) repeating steps b) through f) for each of said plurality of digital video files in said database.