Viral marketing at work! The ad is so popular that it's being remade over and over:
girls have too much time
describing it a recess
nothing better to do at a slumber party?
This, of course, is part of a larger trend where the younger generations feel the need/desire to publicize their lives for public consumption. They take what they find interesting, incorporate (the fancy term is interpolate) it into their lives and then spit it back out.
My key takeaway is that effective advertising to youth markets is more than just flash and fluff. You need a compelling idea (the fancy term is meme) that is funny, or serious, or sad...doesn't matter. But it needs to stick with a few, who can then spread it to others. This is the essence of viral marketing, spreading memes from brain to brain where it takes hold until the next one comes along.