The film was uniquely marketed in that it never use a promotional “trailer”, but many billboards, radio spots, and always a special “road show” treatment on the marquee of the theater. In several cases the film ran over a year in the same theaters. The ad campaign would say “47th great week”, or whatever was the local “hold-over” figure. According to Weekly Variety it was the number one film of a two week period in 1971. In 2006 the domestic film rentals exceeded $120 million dollars. Having taken in about 300 times its budget, it is, in relative terms, one of the all time film financial successes.
The original version was filmed essentially with only a thematic minimal plot. and shown in San Francisco and Los Angeles for a year before national release. The crew was small, and the actors were unknowns, allowing for an initially small budget; as it became a local success, and profits rolled in, the crew would shoot additional scenes and add them to the film. New scenes were shot in both Los Angeles, and Hawaii, to “open up” the picture including on an actual passenger plane interior and cockpit. The self-imposed X rating was a draw in the early stages , attracting viewers to relatively small theatres showing the film. In the last year, with the official R rating it was possible to show the film in 70mm houses like the 4300 seat Boston Music Hall. Total active run extended 3 years and was presented in just over 800 theaters. often outselling larger budget movies in larger theatres. A definitive “R” version was released throughout 1971, and it was played in at least 30 overseas markets eventually.