The "Drink milk" campaign in my elementary school would be a good example. You should drink more milk, doesn't mean you should drink less water, or juice or whatever. It just means drink more milk.

Assuming that you can drink an infinite amount of liquid, yes.

But in practice "drink more milk" means "drink less soda".

>Assuming that you can drink an infinite amount of liquid, yes.

You would also assume that people drink their "max quota" of drinks a day, thus being forced to eliminate something to make room. There's always room for milk my friend.