We are in a small town and serve:
* organic popcorn
* real butter
* an assortment of spices (lemon pepper, garlic, brewers yeast, parmesan, tamari, etc)
* cookies from a local farm bakery
* handmade peppermint patties, choco dipped pretzels, nonpareils, choco covered raisins
* gummies
* sugar-free citrus wedges
* small assortment of commercial candy: twizzlers, m&ms, pb cups
* coffee / teas / hot cocoa
We got rid of our fountain drinks a year ago and only serve bottled / canned (mostly natural) beverages. Everything we serve is free of high fructose corn syrup. Our bottled drinks are $2.50, cans and water are $1.50. (We serve a local bottled water.)
Our concession sales went up this year.
If I could get the proper permit, I would serve some other snacks like hummus / veggies, more pastries or crepes.
It's possible but you really need to know that your patrons will go for it. The big seller is still popcorn!