i've noted that there are several techniques (paradigms, systems, what have you) which propose to increase the force with which a meme impacts upon a given mental landscape. the ones which come immediately to mind include nlp, magick, propaganda, advertising techniques, and conditioning (aka "brainwashing"). most seem to operate by introducing disorientation to the processes which censor incoming information content, though each technique (in general) makes use of a different specific method to create that disorientation (eg propaganda attempts to link the new meme to sacrosanct prexisting memes such as "patriotism"; advertising typically relies on linking the meme to reproductive urges or other reptile-brain processes; conditioning uses an array of techniques from physical exhaustion to exploiting the social instinct). if a memeplex is structured around these "backdoor" techniques, and is also structured to incline the new mental landscape to attempt to retransmit the memeplex, this is a viral idea, a language virus. imagine, for instance, if Coca-Cola could include in its sloganeering the idea that, not only should one think that "Coke adds life", but that one should also convince others of that fact.
founding a religion is a good job, if you can stomach it. good hours, and the pay is great. however, it is a little bit difficult now, due to protective memes (for instance, the concept of "killer cults") which have arisen in the general population, restricting religions to those which either 1) pre-exist, or 2) can be tied to pre-existing religions. witness, for instance, all the hassles that the raelians are getting.
motivational speakers, though, are unaffected by religious xenophobia, but share many of the same characteristics discussed above (such as: those who are "motivated" by the speaker will also typically transmit invitations to friends and acquaintances to listen to the motivational speaker's message).
i think memetics, as a science, also needs to look at biophysical influences of memetic transmission. when a given mental landscape is affected by fatigue or chemical imbalance, the ability of a given meme to have an impact, even a lasting impact, is much greater. if accompanied by repetitive drumbeats, a given memetic packet tends to lodge more easily in a typical mental landscape (see William Sargant Battle for the Mind, among others).
just some random notes passing through my own mental landscape...