>"Apparently you've never been part of the advertisement world or know anyone in it."

It's not just advertising. I'd wager it happens many if not most places where there are contracts to be awarded or specific talent to be retained.

I'd imagine that the folks expressing disbelief are either inexperienced or so obviously 'square' that they're kept totally in the dark about such things.

I've seen one place where it was nearly a standard of 'culture fit'.

Note: I don't mean to condone this sort thing, just to bear witness to its prevalence.