I guess it's been a looong time since I've been to a show that wasn't a hit....
I recently went to a 930 show and the balcony was closed off, even the U-shaped sides.
Thus, the floor was nicely packed but empty upstairs.
I totally get the concept of reducing costs for personnel etc when the crowd size dictates, but it makes the venue more uncool without the viewing options and the nice traffic flow that includes upstairs. Not opening the uptop bar (or even that top level, besides VIP) makes sense, but what is the harm with the main balcony side sections? Is it that much more for trash cleanup after the show? There was already security up there so that's not an additional cost.
It must look sucky to the band -- even if they know the ticket count -- to look up and see an empty balcony. Even one-two rows of people around the Balcony would be pleasant and that would give the audience up there, and the audience on the floor, a little more breathing room and make the place overall look better to the band.
Have they always done this for low-selling shows? Any other observations/suggestions?