Back in the day (aka - during the ccg boom), companies used to just hand out promos when you looked at their product. Some companies had unique convnetion promos, others had a convention version of existing cards. But, for the vast majority you could jsut go check out their booth, maybe demo the game, and grab the promo.
Those days are LONG gone.
Now, for the most part, if you want a promo you either need to buy a product from the booth or you need to participate in an event that awards them. For a company like FFG, that also frequently means playing in the *whole* event, not just entering it.
As much waste as that was, I do miss having a bunch of promo cards for various games even if I didn't play those games myself.