Presuming that you are referring to anti-drug etc. Campaigns....
Fear can be a powerful way of introducing the negative affects of something in context i.e. Road death campaigns are extremely powerful because they introduce an identifiable human life that is taken away instead of just bombarding people with statistics. Successful campaigns need only spend a couple of seconds creating an identifiable character before a negative affect is inflicted on them.
The main disadvantage is that non-threatening advertsing can be completely ignored or mocked constantly, "This is your brain on drugs" is the best example - where people cannot relate to a smashed egg, it looks nothing like a brain and there is no direct mental link between an egg on a counter and you or your friends brain.
Fear can be a powerful way of introducing the negative affects of something in context i.e. Road death campaigns are extremely powerful because they introduce an identifiable human life that is taken away instead of just bombarding people with statistics. Successful campaigns need only spend a couple of seconds creating an identifiable character before a negative affect is inflicted on them.
The main disadvantage is that non-threatening advertsing can be completely ignored or mocked constantly, "This is your brain on drugs" is the best example - where people cannot relate to a smashed egg, it looks nothing like a brain and there is no direct mental link between an egg on a counter and you or your friends brain.