I figured conservative talk might be break even for them, or possibly a very very small profit (running
national ads)...
In many cases, national ads on stations that run national network programming just support the national programming so that the stations don't have to pay for it, or pay very little... and in some cases, the revenue from national ads goes only to the network for that purpose, not directly into the bank accounts of the local affiliates. The locals still have to come up with local sponsors and ads to make much profit for themselves, which was probably a tough go for conservative talk on WTTT.
One caveat: Salem Communications is a publicly-traded corporation on one of the major stock exchanges. Not only INDIVIDUALS, but private and governmental pension funds have invested (foolheartedly) in Salem's stock. Thet have a fiduciary responsibility to "manage" their business with some degree of rationality...this move doesn't seem to qualify, UNLESS they know that Clear Channel will definitely flip WKOX-AM once the move to 750 Sawmill Brook Parkway takes place.
I wouldn't venture to guess that investing in Salem would necessarily be "foolhearted" (foolhardy?). I'm sure several of their Christian stations nationwide, and the network overall, is probably quite successful.
Also, as for Clear Channel locally, "Rumba" on WKOX is a Spanish musical entertainment format, not a religious format. "Radio Luz" on WTTT is a Spanish religious format. Though there may be some crossover, the formats will have largely different audiences, so it may not matter to WTTT whether or not WKOX remains "Rumba" from their new transmitter site.