Making memes and publishing them are not always the end goal. There is another tool/process these memes can utilized: query. Queries include linguistic questions, but aren’t limited to them: they can be roughly abstracted to “a request for information.” This includes all types of normal questions, but also such things as politics and life goals.
There is a particular class of queries: queries about queries. For example, When some is deciding their opinion on something, asking them a loaded question about a politicians morals can go a long way.
Memes become toxic/cancerous/parasitic when they supplant questions. The answer to a question might be what a person thinks the meme is after, when the real intent of the question, is to change the persons opinion on what is being talk about. The memetic war in a sense could be thought of as a war on questioning itself, a war on selection: the idealized viral meme would make perfect copies of itself endlessly. These queries could invoke both positive and negative thoughts and opinions
To invoke a positive thought, a sale man always ask questions about how the person feels about the product, or what they like the most about the product. These intern make the person think about the good traits of the product, and could convince the person to purchase the product.
There are ways to evoke negative thoughts. If someone wants to steal a girl, from a guy, all they need to do is keep asking about the negative features in a guy. The girl will then be forced to think about the negative side of her relation ship, and would be more likely to break off the relationship for something better.
Good introductory information: http://plato.stanford.edu/entries/questions/