One thing to keep in mind about the Tyler-Longview market is that the majority of stations in the area are not receivable in the entire DMA. It is composed of Gregg, Smith and Cherokee County, which is a very large area. I suspect that things were more accurate when Tyler and Longview were considered separate markets.
Several stations that show up in the ratings are not located in any of those counties. Obviously, they have coverage and listeners in their home area, yet that is not counted. Those that do cover the entire area, like KOOI, get an unfair mathematical advantage when the ratings come out. If you don't have a "flamethrower," you need two full power stations to cover the majority of the DMA.
Stations that don't enjoy that advantage may have respectable listenership, but will never do well in the Arbitron ratings. There must be a better way to figure this out...