Sociology notwithstanding, on the Internet, a "meme" (pronounced "meem") is usually described as a catchy derivative of some aspect of pop culture, parodied and repeated to the point that its origins and original meaning become muddled and completely mutilated beyond any point of recognition or humor. It can even be Wrongfully Attributed. Which means we don't want them in All The Tropes articles, because we are not interested in being muddled, dated, and beyond humor. For in-universe examples, see Instant Web Hit.