Check Guns n Roses upcoming shows on ticketmaster. I believe I counted something like 30,000 unsold seats for the Denver show (NOT including resale tickets).
Last year's shows mostly sold well for GNR, but the hype has clearly worn off. Cities like Miami have 10,000+ unsold seats, whereas U2 sold out a bigger stadium in 1 day. GNR might still end up with one of the top 10 grossing tours of all time, so it just goes to show ticket sales don't mean everything.
Did you see the attendance for Guns' second show in Boston last year? I think it sold about 25 percent. They ended up closing off the entire top section and upgrading people who had bought nosebleeds to lower bowl.
According to the Wikipedia page on the current Guns N' Roses tour, the "Boston" shows sold 65,472 out of 71,098, earning $8,302,575 in ticket sales.
While I assume that the opening night was either at or near capacity, with the unsold tickets primarily being at the second show (I know that this happened in Chicago, which sold 82,172 out of an available 96,088 tickets, earning roughly the same amount as Boston: over $8-million), that is still the definition of success by any measure.
As I've said again and again, as best as I can tell, both the Louisville and Pittsburgh shows are at, near, or slightly above 90% in terms of ticket sales.