I suspect most of us would be surprised at Syracuse's fan base.
New York State has about 19 million people. Almost half of those are in the city, which who knows what teams they follow. But once you get upstate, with the other roughly 10 million folks, it's all about Syracuse University. From Buffalo to Albany to Binghamton, and everything in between, it's all about Syracuse.
So there's a potential fan base one and a half times the size of the state of Tennessee's population. They simply have a larger base to build from.
And yes, folks there follow football. Basketball is #1 to Syracuse fans, of course, but football is a bigger draw for them than many of us seem to think.
So yeah, I'm not surprised they're on that list. I agree with Ricky, though: Tennessee is being sold short in that count: I've always heard our fan base numbers in the mid-4million range, like 4.5 give or take.
Go Vols!
EDIT: And p.s., Tennessee's population has boomed in the past few decades, from below 5m in 1990 to more than 7m today. A lot of those folks are transplants from other states, and bring their loyalties along. But some of them will embrace the local lads, and even more of their children and grandchildren will.
So when I said the Vols' fan base has long been 4.5m or so, I think maybe that's getting dated, too. We might be significantly higher, maybe above 5m by now. Need a new survey by folks who know how to run valid ones. And no, not by some station up in Connecticut whose employees tend to think anything west of Philadelphia is just "fly over country" populated by trailer parks.