The New York Times answers the question. Sara Boxer writes...
The Web is obsessed with anything that spreads, whether it's a virus, a blog or a rumor. And so the Internet loves memes.
Memes (the word rhymes with dreams and is short for mimemes, from the word mimetic) are infectious ideas or any other things that spread by imitation from person to person - a jingle, a joke, a fashion, the smiley face or the concept of hell.
The World Wide Web is the perfect Petri dish for memes. Wikipedia, the free collaborative online encyclopedia, calls the Internet "the ultimate meme vector."
