My restaurant is full every night — why is there no money in the bank?

Because the queue measures demand and the bank measures structure. Between the two sit channel commissions, discounts, food cost, labour, rent and the timing of cash itself — each takes its share before anything reaches you. A full room can sit on top of a structure that loses a little on every cover, and volume then scales the loss rather than curing it. The honest response is to read the numbers behind the room, not the room itself.

From A Busy Restaurant Can Still Be a Bad Business — the full reading, with the method behind this answer.