Ah the age old, "if only they let me be in charge, I'd make things better" line, spoken on an online message board, from someone who has how many years marketing experience for a D1 AD?
I think its more about the highest bidder and where their advertisements will go than anything. Plenty of businesses do advertise but we just don't see them as often.
Also, the amount of businesses and money spent helps keep costs lower than others while putting a halfway decent product on the field.
MU doesn't have much to choose from, given WV as a state hates businesses and making money. So places like Dutch Miller who (regardless of what you think about him) does sell quite a lot of cars and has the money to burn, will be top business advertised and can influence when spoken of during games...regardless of if we like it or not.
If WV had more businesses to advertise, it would certainly be interesting to see how much more money MU could make.