Okay, this makes perfect sense.
I can fly from Louisville to Cincinnati, then from Cincinnati to Cleveland, and return home with another stop in Cincinnati, for $201.30.
Alternatively, I can just drive to Cincinnati and take the same flights between Cincinnati and Cleveland, then drive back to Louisville, for $237.40.
So essentially the flights between Louisville and Cincinnati are not only cheap, they will actually pay me $36 to fly on them.
No wonder Delta is having financial troubles.