Tickets and food
A card generally covers admission and the concession stand. Being able to pay for food as well as the ticket matters more than it sounds, because concessions are where a cinema trip actually gets expensive.
Tell the recipient the card covers both. Many assume it is tickets only and pay cash at the counter.
Online booking fees
Booking online sometimes carries a per-ticket fee. Where it does, a card may or may not cover it depending on the booking flow.
Buying at the box office avoids the question entirely — worth mentioning if the balance is tight against a specific outing.
Premium formats
Large-format and premium-seat screenings cost considerably more than a standard ticket. A card sized for two standard admissions may cover one premium one.
If the gift is meant to be "a night out for two", size it against the format they actually choose rather than the cheapest one.
Subscription tiers
The chain runs a monthly membership with included screenings. Whether a gift card can pay for that membership varies — if the recipient goes often, the membership may be the better gift than a card, so ask.
Region
A United States chain. A card has nothing to apply to elsewhere.
Amount
Count visits. A card worth four or five admissions for a couple is a genuinely good present that costs less than most alternatives, and it gets used.
Who it suits
Couples, families, teenagers, and the "person who has everything" — it buys an evening rather than an object. See experience gift cards explained and gift cards for people who have everything.
Asking for one
Confirm a US recipient and tell us the amount.