Most collection of data is automated (developed in Britain and misused by Facebook). Amazon is an easy example. Type in some ancient b-flick movie with breasts and monsters, even if most of your viewing has been blockbusters, and they will bombard you with ‘films based on your search for 20ft Lesbians from Mars’ or whatever it was. They then sell your ‘preferences’ to other companies who will then spam you with such short.