SLU is 3rd on the totem pole in Missouri when it comes to D1 schools in state. Ask anybody who lives in Missouri, it goes MU, MSU, then SLU. Now SLU doesn't think that way, but they are a little different anyways. The MVC mid major compared to A-10 is a little off, other than markets they are pretty similar.
What I'm talking about SportsKC is who is the #1 Division 1 basketball option in the city. SLU is the only Division 1 program located in the city of Saint Louis. The statewide teams probably have a greater overall following in St. Louis, but that is besides the point.
The setup of the A-10 is different from the MVC with a lot of universities that are the second banana for basketball with in their respective cities.
A-10 tier breakdown.
Georgetown, George Washington*
Villanova, La Salle*, Temple*, St. Joe's*
Providence, Rhode Island*
What you have is about 50% of the A-10 being second banana basketball options within their respective cities.
The MVC schools don't have any second bananas, hence they have great attendance.
The MAC is much the same deal as the MVC except for Eastern Michigan being in the same county as UMichigan. The difference is the causal fan rallies around football in the MAC while its basketball in the MVC.
While they are the only team in the city, still means they are competing against the statewide flagships.
As far as the Bradley/Illinois State portion of the MVC, those two schools are only 40 miles apart, and U Illinous is only 50 miles from Normal, IL, and 90 miles from Peoria, plus there is the neighboring Decatur and Springfield smallish metro areas that could be the source of a concentration of fans. So in this Central IL Megalopolis, U of Illinois is commutable in an early evening/night to a U of Illinois bball game that when you say it is the only game in town, it really not as these MVC schools are competing for fans with a Big 10 team in all these Central IL metro areas, thus, they are more likely to follow U of Illinois, due to their larger alumni bases and the larger market appeal of the higher order conference of the Big 10.
In the MAC, you have pairs of MAC teams competing with each other in the same metro area, which is in essence the "same town". Bowling Green is a mere 20 miles from Toledo and is in the Toledo metro state area. So BGSU and UT are in the same town in the same market and have tons of U of M, Ohio State and some Notre Dame and Michigan State fans. Same with Kent State and Akron, same metro area and about 15 miles from each other. If you live there, take your pick, plus Ohio State, and then you have Cleveland State and Youngstown State both within commuting distance (a mere 50 miles either way). In the Cincy area, you have both UCincy and Miami in the same metro area, plus OSU support and Dayton and Wright State are really commutable.
Ball State is not far from IUPUI, Butler, and IPFW. Eastern is definitely in the deep shadows of U of M. Central Michigan is 1 hour from E. Lansing and MSU and Kalamazoo, home of WMU is a little more than 1 hour from MSU. WMU and CMU are somewhat in the shadows of Michigan State. Ohio U is 75 miles from Ohio State. They have some support in Columbus, but not on the level of Ohio State. NIU is in the shadows on not only U of Illinois, but all those Chicago based teams.
They are casual fans, but even on the local level are not too separated from a comparable competing team or completely are separated from the locales of major state flagship schools.
Even in the MVC this is the case. Lincoln is commutable from Omaha, Iowa State is easily commutable from Drake's town of DSM, UNI is not far from Iowa in Iowa City. I knew a number of UNI grads that preferred to root for Iowa rather than their very own school. They were just going to school there. Indiana State is not more than 1 hour from IU and Bloomington. There's not much separation of either one of these conference schools to call them the only game in town given commutable proximity of these schools from the state flagships.