Although we'd all prefer our shirts with no sponsor on it, the club would consider any deal going if they didn't have many/any options. A small amount of money is better than nothing.
Can't remember the details about Airdrie's deal.
I don't know too many details, and I'm not sure whether the charity put the idea to us, or if we went to them. It is a charity the club have done publicity with before AFAIK. They were trying to raise the cash for some kind of sponsorship starting next season and would receive a small percentage from each shirt sale, probably £1 or something.
But if the club has nothing else or the charity could secure funding from somewhere, it could happen this season.
EDIT: It could also be that it's only for the sponsorship on 1 of the kits and we could have a different sponsor for the other kit. (Not something I heard in relation to this, just something that a few teams do these days, and again might help go towards covering the shortfall.)