I'm secure enough to admit how lame I am - that I was exposed through Arcade Fire because of the trailer to Where the Wild Things Are. Strangely, the song isn't actually in the movie at any point.
I then made the beginning of Wake Up into my iPhone ringtone. Did the principal of one of my schools make fun of me for my "weird chanting music"? Perhaps. Was I annoyed that she'd put down my music? Perhaps.
The complicated textures of a song that carries a simple melodic line appeals to me. The chorus doesn't actually have any lyrics; very convenient for a person like me who can't remember the lyrics to ANYTHING. The simplicity of both the "lyrics" and the line floats above a percussive line, guitar chords, and strings - all of whom have their own part. It's not just doubling; it's not just a harmony.
Added to that, a little before the 4 minute mark, the song changes tone all together and the drum beat kicks us into a more upbeat and lively feel.
Arcade Fire is quite the interesting group, if you investigate their music further. While Wake Up is arguably their most mainstream hit, Arcade Fire is a music group intent on their own explorations.