Those numbers are absolutely 100% right, they're from Korea's official Gaon (modeled after Billboard) charts.
Korean numbers are simply extremely high for three reasons
1) The digital market has always been huge, and physical product sales have gone down so far since people just download all the songs.
2) Digital downloading is completely illegal in Korea and, as I understand, pretty strictly enforced. (What I mean to say is that, unlike in many territories where only the one who offers the illegal downloads can be prosecuted, in Korea the downloader can also be prosecuted)
3) Songs are quite a bit cheaper than in most of the world.
But they are still sales. For example, the best-selling song last year was from 2am, and sold over 3 million copies. It's simply a big digital market.