If this was mentioned before, in my defense I did search for "BOGO":
My big consumer pet peeve is "Buy X, get Y free!", because FREE means at no cost. If I have to buy something, then you're not really giving me anything free, are you? For example, if it's the classic buy one, get one "free", then they really should have to call it "buy two, get 50% off"!! If there really is a "free" item, can I have just the free item? No? THEN IT'S NOT FREE!!!
Some people look at me weird when I complain about that, but I figured this crowd would be more likely to get it.