All donators, and staff were allowed one submission as a factoid. The ad info page states:
Interesting facts, funny quotes, hints, info, and ads given away to supporters.
Do note, the latter part of the sentence. However, whether you disagree with that is another matter, but that's why you're seeing these types of
factoids. There's also some that are funny ones or at least meant to be funny.
They probably shouldn't be called factoids for this reason, but I don't think that's a massive problem. Most users know them as adverts rather than factoids I should imagine.
I imagine it was a way of saying thanks to those that have contributed to the forum, whether monetarily or via helping out with forum related duties.