can anyone help me out here? A friend of mine is convinced that it came from porn and has just seeped its way into mainstream vernacular. I think it was probably a film term and porn directors adopted it for their own uses.
Thoughts?
Maybe the male actors were only paid on delivery of the ‘goods’? I would google the term to see what comes up but i’m pretty sure I can guess the outcome of that little excursion.
I do think it is from pron (oddly, though, OED let me down on a cite).
It strikes me as just expressing the pron audience’s feeling that they “hadn’t gotten their money’s worth” until they explicitly saw the, er, climactic event (this also jibes with the fact that said event has to take place all over someone’s face or belly, apparently, and not in more conventional locations).
And now . . . my doubt proves disloyal and ill-founded:
From online edition:
money shot U.S. colloq., a provocative, sensational, or memorable sequence in a film, on which the film’s commercial performance is perceived to depend; (spec. in a pornographic film) one showing ejaculation (= come shot s.v. COME n.1); (also, in extended use) a crucial or pivotal moment, event, or factor, esp. in another art form, as a novel.
I heard this term with reference to non-porn movies prior to its being used for the moment of climax in adult films. Specifically, as Huerta88’s cite suggests, it’s the big spectacular moment of the movie that is designed to be shown in the trailer to grab people’s attention and make them want to see the movie. For example, this would be Harrison Ford jumping off the bus before the train hits it in The Fugitive, or it would be the bomb’s-eye-view dropping onto the ship in Pearl Harbor. Many different trailers were cut for these movies, but those two shots appeared in all of the trailers for their respective films. Hence, it’s called “the money shot” because of its promotional value in terms of attracting people to the box office.
This is just my personal experience, though. I have no better cite and it’s certainly possible that the term originated in porn before migrating to mainstream films rather than the other way around. I’m genuinely curious about what might be turned up.
I saw the term in the porn context long before either of those films came out. I don’t remember where, though - possible in a magazine article or something like that. How’s that for a cite? 
I would have bet that we did this one before, but the archive says no.
The current earliest print cite is 1977, and it’s in a porno source. But the current thinking among etymologist is that it probably started in Hollywood films and was adapted by the porno industry.
I did a search among all the word sites I have bookmarked. Oddly, none of them even discussed “money shot.”
But on one site I got the usual ad links that automatically include the searched-on phrase.
So I got an invitation to “find money shot auctions on e-bay.”
Not gonna do it. Wouldn’t be prudent.