I tend to think that the effectiveness of advertisement and memery really depend on the context. When it comes to something where a choice has direct effects and costs - when buying a plane ticket or an appliance, for example - there is a strong incentive to discern true information and disregard advertising fluff. This is because one's own choice is the determining factor, and a poor choice has clear consequences. But in politics? A single vote is astronomically unlikely to influence anything - so voting is evaluated socially, expressively. Its benefits and costs are what it does for one's self-image, or group membership, or whatever. So there's not much incentive, for nearly everybody, to sort the real from the imaginary when considering politics. That's the kind of environment in which meme magic flourishes, because believing does make it real - real enough for its purposes. This also means that it's nigh-impossible to design or predict success in this sort of information distribution. When your content is made real or unreal by raw imagination and social dynamics, most of it is, I think, a case of people succeeding accidentally and claiming later that that's what they meant to do all along. So it can be powerful - but is almost impossible to control in an organized way.