(Some of the others are probably not aimed at my demographic… )

Of those three, the “Got Milk” campaign was mostly a waste of advertising money. I cannot imagine that anyone was induced to think milk was cool, or drank more milk as a result. Even if a few did, probably not enough to repay their ad-dollars. So, everyone remembers the line, and doesn’t do anything about it.

The other two are great lines because they integrate with the brand-images of BMW and NIKE. The Milk one is a fine line, but it is just a line, just a floating abstraction.

The one that I recalled after seeing the answer was, the Wendy one:
2. Where’s the beef?*

Do they still use this? It made sense at the time, because it fit with their brand image. It definitely was not floating. People would agree that they really had more meat in their sandwiches. I think they’ve strayed since then.

The essence of a good slogan is that it should reinforce the brand. When one hears it, one should go: “yeah, that’s true! that’s a good way to put it.” Thinking “that’s funny!” or “that’s cute!” won’t cut it; it must ring true.

It is analogous to the formation of concepts and principles. The brand name and the slogan work if they reflect the reality of the brand image, and *then* encapsulate it in a pithy way.