I would submit that it can also depend on your home airport, and it's geography relative to the hub of the airline to which you are loyal.
EX: I live in San Diego and am loyal with Delta, so I'm usually flying through JFK or ATL. For me, a higher cpm is okay if I don't have to fly SAN-SLC-MEM-DTW-JFK and can just fly SAN-JFK. As always, Your Miles May Vary (YMMV)