Because theaters make very little money on ticket sales. The money they need to make to stay in business comes from sales of food and drink. You don't have to buy what they offer, but the theater is theirs, so they don't have to allow food and drink bought elsewhere.
You can you just have to hide it. I do all the time.
It would be nice if the theater was more accommodating about their offerings. I've asked for years that they offer diet, caffeine free soda. All I ever get back is defensive nonsense about why they can't get caffeine-free diet coke or diet sprite. And paying $8 for popcorn? That's not profit, it's a rip-off.
Because theatres rely on the revenue from snack sales to operate.
You buying concessions at the theater is how theaters make money.
This is the policy everywhere. It isn't new. If you are in anyway furtive about it none of the kids working the door want to turn you away though.
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