'I graduated with a degree from the School of Hard Knocks' which sounds like it ought to have been written by Carlotta Campion....
The things we do not know when looking at the grosses as they are printed on-line are what the potential gross for a show is--ie if all the seats were sold at full price, what the total amount would be--and what the weekly breakeven for a show is.
100% sold is great, and Hairspray is selling out with no promotional discounts at all. If a show sells 100% of the seats but no one pays full price, they won't make that much money. Who pays full price for Phantom anymore except on a Saturday night?
Some shows have a very high breakeven each week. The bigger the cast and the more complicated the physical production, the bigger the cost. Aida probably has a big operating cost, so does Millie, Beast, Gypsy, and The Producers. Movin' Out has roles that are double cast and a set that moves in a major way. Every time something moves, think that it cost money to make it move.
On the other hand there was Proof: 4 actors on stage, one set where nothing flew or even moved. No wonder it ran over 2 years even with plenty of discounts.
Ain't Misbehavin' for the last 18 months of its run was a perfect example: cast of 5 (no stars) plus 5 understudies, small band, plus crew, a simple set and one costume each. It made a few dollars each week and everybody was happy.
Chicago is a very cheap musical to run.
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher