In reading past posts, I found the "Black Holes" useful.
I am with Comair, a "Delta Connection" carrier. With the Delta bankruptcy and the cutback in flights both mainline and with the regionals, non-rev has become a real issue for the CVG/ATL and ATL/CVG legs. On one day, a CVG/ATL flight was overbooked by 37 and there were 58 on standby and 45 of those on standby were confirmed passengers from a previous flight.