Actually Spartanburg is relatively close to Greenville. The two of them make sense together. I think the whole market is not that much separate from Charlotte actually. Ashville is more the outlier. I guess they get their TV from Greenville because it's the closest city of any size.The difference is that Spartanburg is too small to have its own TV stations, and therefore gets TV from Greenville. Thus, it's part of that media market. Richmond and Hampton Roads have their own TV stations. Newport News is closer to Norfolk, so it gets TV from there. Williamsburg is the weird one. It's halfway between Richmond and Norfolk, and I believe they get TV from both, but I think it's lumped in with Richmond for media market purposes.
Another thing regarding your issue about Spartanburg being so far from Greenville: you should see some of the media markets out west. There are areas 3-4 hours away by car from the city that are considered part of the media market due to lack of population.
Hampton Roads would be pulling all of Nor, VA. B, Ches, Ports., suff., Hampt, NN and I would include Williamsburg in with Hampton Roads since it virtually borders NN. Plus a large portion of NE NC, from Gates County east and down to Edenton and the Outer Banks and in VA west to South Hampton and North to the Eastern shore of VA and the eastern Middle Penninsula and Northern Neck. That's 2 mil+ population. I am not seeing G-ville, Sparty, Ashville being larger than that without somehow claiming a lot of what I would think of more as suburbs of Charlotte.
Greenville is certainly a growing area with it's being along 85 between Charlotte and Atlanta, but not there yet.