I agree, "why some things propagate and others don't" is a very interesting question. I enjoy contemplating on the variety of propagating things inductively--jokes, poetic phrases, turn of phrase, but also skills, techniques, basic knowledge--just say the phrase Org Mode sets up the cult of the organized for preaching the gospel of Emacs. haha.

Though, my curiosity in meme propagation is preempted by the curious rejection of memetics as explanation for social or psychological phenomena outside of its adherents.