I've posted this general sentiment before, and it's worth repeating occasionally, especially when the subject of attendance comes up. It's understood that, as I and others have noted, the world has changed, attendance is down everywhere, and people are generally less inclined to go out these days. It's also understood that the program has experienced a chronic, generational decline in interest and relevance in the community. For both of these reasons, past experience won't necessarily apply anymore.
That said, past experience does tell us that winning matters, and attendance has come back rapidly when the team has recovered from down years. Data on actual butts in the seats (as opposed to paid attendance) isn't easy to find, but you can glean some things from the official ticket sales. The most prominent example is the Gophers' success in the early 80's (conference title in '82) followed by the Madison scandal, Clem's teams' struggles in his first two years, and the rebound of Sweet Sixteen and Final 8 in his 3rd and 4th seasons respectively.
I came to the Twin Cities campus (from Morris) in 1986, Clem's first season. Actual attendance was way down. Haskins famously stood in the lobby of the Bierman building handing out free tickets to anyone who'd take them, trying to get butts in the seats and re-establish a home-court advantage. My roommate grabbed a couple, and we attended the Indiana game. There were only a few thousand people there (much like you see today, if not worse), and we schlepped our way well down the first level. A dark cloud remained over the program because of Madison, and I remember there being little energy in the building, although my recollection could be off. It was a low point, though.
Three years later, the building was nearly full, the team was ranked in the top 25 on their way to a 6-seed in the NCAAs. That was before we bought season tickets, so I had nothing to compare it to, but we attended Senior Day (Michigan State), and I don't know if I ever experienced anything that loud in my life up to that point, and I'd been to rock concerts. Within a couple years after that, season tickets were all sold, and there was a waiting list.
Some of that was a matter of ticket holders coming back to games again after the scandal and the swoon of Clem's first couple years. But much of it was new ticket buyers, and it was because the winning and excitement had returned. The team and their style of play were exciting, and you knew they were going to have a chance to win in every home game, no matter the opponent. That's a saleable product.
It's amazing what winning will do to attendance. Not that there will ever be a waiting list again with how the world of sports has changed, but it will bounce back suddenly and steeply once the program is in better health, I guarantee it. People in this town are hungry for a winner, and college basketball is one of the best sports products in the world.