So how exactly did popcorn become the signature snack for movie theaters? As opposed to peanuts, potato chips, candy bars, the usual stuff?
Cheap, easy to produce fresh and by the bucketloads on demand, and all thus high in profit and demand. I would guess it originated with circuses, perhaps moved to vaudeville and from either/both to movies.
It doesn’t make much noise when you eat it.
Combine the above with the fact that it is easily kept warm, doesn’t stale rapidly, conveys massive amounts of salt (to promote soda sales, which have an even higher ROI)and can be popped and bagged in advance so there isn’t any slow-down during the intermission rush.
If anyone is interested, you can re-create that movie popcorn flavor by using coconut-oil to cook it. Clear or yellow-dyed will work, but if you use the yellow-dyed, it will come out looking like movie popcorn, too.
Added bonus: you can keep it for a week and re-heat it if you cook it in coconut oil and it will still be fresh! (another reason ball parks and movie houses use it)
What is ROI?
Return On Investment.
My question is how did movie theater popcorn get to be so expensive? The day before New Year’s Eve was the last time that I was at the movie theater in my area and their popcorn was about $6.25 for I believe the smallest bag of it. 
God bless you always!!!
Holly
P.S. I was able to get some because I had gift certificates and to me it was really good, but in my opinion, it wasn’t worth how much you have to pay when you don’t have gift certificates.
Um, who ya blabbing at?
When movie theaters stopped making much money on ticket sales.
You could dig out a tub from the trash. 
Putting out a question about the subject of this chat for anyone who could answer it is what I was doing there. If you, didn’t have an answer for it, what is the purpose of the message that you have left for me here?
God bless you always!!!
Holly
If you have a problem with another poster, take it to the Pit.
Thanks,
twickster, Cafe Society moderator
Vendors used to sell popcorn to theater customers from portable carts out in front of movie theaters. Early movie theater owners thought selling snacks inside was gauche because live performance theaters didn’t do it and they wanted their business to have same respectable atmosphere. At some point they realized that they were passing up additional revenue and installed their own snack bars. Cut to present day where the snack bar brings in more money than the tickets.
Huh? Nope, no problem here and no need for the Pit. I asked who she was blabbing at because she seemed to be replying to someone yet no one said anything to which a reply would be appropriate. What’s the problem?? 
True that. I went to a second run dollar theatre, $2 to get in, $23 for corn and soda.
My first job was "candy"girl at a movie theatre. They didn’t pop their corn, but rather put it in a warmer. We had mountains of bagged corn in the basement. The mice loved us.
My understanding is that the production company gets most of the ticket revenues for the first few weeks of a movie’s theatrical run. So the theater owner counts on concession stand sales to make money for these movies.
It’s much more complicated then that.
Ballpark, a studio gets 50 - 55% of the total take. So if film grosses 100 million dollars, the studios get back 50 to 55 million.
Keeping 45 to 50% of the ticket money is no small change.
In the 90’s many of the chains consolidated. Now Regal, AMC and Cinemark are very large and they really have negotiating power with the studios.
Actually those chains make more money on the 20 minute program that shows before the movie than they make on concessions or ticket sales.
I don’t know about the modern day economic structure, but back in my day the percentage of tickets sales changed as the run of the film went along. The studio got a high percentage the first week with the percentage decreasing for them and increasing for the theater from week to week for as long as the film ran.