Restaurants offer a special "value" menu in this period. Basically, they serve cheaper stuff. Servers brace themselves for a lot of work and low tips. Volume goes up, margins go down.
A lot of people are excited about restaurant week. Yet even if they eat at a nice restaurant, they aren't eating the food that makes that restaurant's reputation.
A lot of people who like to eat good food stay home during restaurant week, if only because their favorite haunts fill up with dilettantes.
My experience of restaurant week: Mangalitsa (aka luxury pork) sales crash during this period.
It reminds me of one person's comment on twitter, "Who wants some Mangalitsa Pork? The most rare/expensive pork money can buy. People hate ballers these days."
When I see Mangalitsa pork popping up in spoofs about pretentious restaurants, I cringe:
How does it work? Exactly 19 lucky souls (chosen at random from the membership rolls of Match.com and the New York City Municipal Credit Union) gather on the corner of Keelhaul Terrace and St. Flocellus Street in the Rottenwood section of Brooklyn exactly 19 minutes after sundown every evening (a security force of pensioned-off Guardian Angels enforces the temporal parameters), mill around aimlessly until the unmistakable rat-a-tat-tat of a driveby gang shooting is heard from two streets over, and then line up in ascending order of height along the curb while Blutwurst and his team race by on their vintage Schwinn Couriers and toss exquisitely crafted morsels (Mangalitsa pork-fat shooters, rattlesnake-and-cannabis hand rolls, rabbit tartare with catfish-liver crostini, and the like) — though never quite enough of them to go around —into the air above their heads. Hilarity ensues.