Kpop's rise to fame amongst "western" audiences.

Kpop is perhaps the most popular non-English music genre amongst western audiences. What makes it so popular amongst western audiences? Is the music composition and style similar to western music? Why are their music videos so popular on Youtube, a predominantly English-speaking site? How is their image construction similar or different to popular western boy and girl bands? Look at the factors that make kpop as popular as it is and it's history abroad (maybe even extending to other Asian countries where it is popular, like Japan).