Most Koreans are interested in streaming services, not downloading. Streaming video, Podcasts, movies etc.
On top of that the system works underground in the subway
and on top of that there's digital tv everywhere also
https://en.wikipedia.org/wiki/Digital_Multimedia_Broadcastin...
Many phones in Korea support DMB (and it also works on the subway).
EDIT: Someone's on a downvote party for my comments today I think.