Local direct sales are what seperates the sellers from the order takers. If you put a mob in the client's store, he got value for his dollar and he will keep buying your station. This will happen when the seller approaches a client appropriate to the station's audience. So, whether you need ARB or not depends on the amount of national business a station does, to a large degree. In that religious stations tend to have rather more loyal audiences than non-secular ones, they would have a better chance of survival without using ratings. Whether that's a viable choice in a market this size is debateable... but I'd love to see Epperson/Atsinger/et al give it a try and show success.
I notice when the Spanish speaking folks elsewhere dumped encoding, Arbitron promptly took them to court over it.