When every seat matters

Reserved seating is the right answer when the view is not the same everywhere in the room. A concert hall, a theatre, a long table where being near the top of it matters.

When it is the wrong answer

General admission is faster to set up, faster to sell and faster at the door. For a standing room, a picnic or a gallery, a seat map is work nobody asked for — and it caps a room that did not need capping.

The question to ask

Would two people pay different amounts to sit in different places? If yes, you want a seat map. If not, you want general admission and a shorter queue.