Every corner of the globe, it seemed, had become obsessed with Psy's viral hit in 2012.

But despite two successful follow-up singles and promises of a US-produced album, there has been very little noise from the South Korean rapper since.

K-pop was officially on the map, but did its unofficial ambassador give up?

Hardly. Having earned an estimated $55m (£36m) from his work in the West, Psy is now racking up similar amounts from the lucrative Chinese market, where his collaboration with world-class pianist Lang Lang is currently producing a run of consecutive number ones.

"Chinese fans love his music and the song," Hyun Suk "YG" Yang, his manager and founder and chairman of one of Korea's biggest entertainment companies, YG Entertainment told the BBC.

"It topped [all the] Chinese music charts."

Psy's decision to focus on the Asian music market may be an indication of where the entertainment industry turns over the highest profits for musicians - China's entertainment market was last valued at $95.7bn - but it also put a sudden end to the epic K-pop tidal wave he was supposed to be riding in to the West.

That could be about to change.

Talent manager Scooter Braun, who discovered the likes of pop megastars Justin Bieber and Carly Rae Jepsen, told the BBC that it was Psy who opened his eyes to South Korea's hottest commodity and its line-up of talented idol stars ripe for export.

When he first saw Psy's Gangnam Style video "something in my gut went off" says Braun, who immediately signed the singer to his US-based label, School Boy Records.

"K-pop as a genre invests a lot in their music videos, with unique and vibrant visuals and even a bit of an exoticness to them," he says.

"These larger than life visuals allowed fans who may not understand the language to still understand the music."

Which explains why, with virtually no marketing whatsoever, K-pop music videos continue to rack up millions of daily video views by overseas fans, many of whom simply discover the genre by chance.

In fact, more than 90% of K-pop YouTube streams are now consumed outside Korea, many in North America.

"The fact that fans around the world can see content online is really helping to establish K-pop outside of Korea and Asia," Braun says.

As are the K-pop concerts. South Korean boy band, Big Bang's 2013 Alive Galaxy Tour performed at 48 international stadiums, including sold-out shows at London's Wembley Arena.

(BBC News)