I keep thinking that, literally over and over in my head. Take the Semi Final in 2019, or hell, even the Irn Bru Final in 2018, obviously you've got the regulars who are at every single home game or whatever, then you've got dozens (or in 2019, probably hundreds or even thousands) of faces that never get seen again at any of our games. It's almost as if they don't actually care about the club unless it's a big event, and I can't think of a whole lot of solutions to get them into the games.
Aside from giving out tickets at schools, I think another way could be a "sampler ticket", where at the start of the season a voucher gets sent out to every household in the Inverness-shire area as a "good for one free game" type of thing. Don't know how much it would cost, but it could give a decent shot at people deciding to stay on and get season tickets or whatever.