For a while, it was impossible to move without Gangnam Style pounding the eardrums — whether it was SuperBowl commercials, flash mobs, primetime TV performances or mobile ringtones chiming away, writes Omid Scobie, an expert on the entertainment industry and K-pop genre.
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.
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And for those still unaware of the genre, Braun's next discovery could be about to change things. Step forward 24-year-old Korean pop sensation, CL.
Hailing from one of K-pop's biggest girl groups, 2NE1, the singer and rapper has more than 45 million Asia single sales under her belt and is already a favourite among US producers and elite fashion designers.
Moschino's creative director Jeremy Scott, who has worked with the likes of Britney Spears, Katy Perry and Rihanna, credits her as his muse.
"My team first saw CL perform with 2NE1 in Seoul at one of Psy's concerts," says Braun. "We were extremely impressed with her stage presence… [she's an] amazing performer.
"We wanted to help her bring her talent to the US," explains Braun.
So, can CL singlehandedly drive the K-pop takeover that Psy almost pulled off?
"I grew up listening to English bands and American pop," CL says.
"Now that I've been an artist in Asia for eight years, I feel like challenging a new crowd. I definitely have a long way to go, but I feel like I have the right people around me, a good team."
Plus great connections.
In the past year, Braun has helped CL (real name Chaerin Lee) rap on tracks for producers Diplo and Skrillex. In April, she appeared alongside young Hollywood's elite, including Bieber, Kendall Jenner and Ariana Grande, for a viral video style lip-sync cover of Jepsen's I Really Like You.
Last week, her collaboration single with Diplo, Riff Raff, and OG Maco, called Doctor Pepper was released.
Diplo, whose back catalogue includes hits for Beyonce, Madonna and Chris Brown, calls the hip-hop track "the right balance between glossy K-pop attitude and keeping CL positioned where she belongs - as the baddest, coolest female out right now."
Like many idols in the K-pop industry, CL began training with her agency at the age of 15.
Trainees are expected to juggle school and long hours of daily practice, which include singing, dancing, acting, language classes and, in extreme cases, plastic surgery makeovers.
It is a gruelling process that can last years before an artist is deemed ready to debut though the rewards for those who succeed are worth the intense training periods.
Korean entertainment agencies are known for signing artists to golden handcuff-like contracts, anywhere from seven to 13 years.
These guarantee long and profitable careers for the artist and a lucrative return for the agency, who will have spent seven-figure sums on training.
2NE1's label mates Big Bang, a five-member male group who debuted in 2006, reportedly earned $71m in 2014, just $4m shy of One Direction in the same year.
But for every success story there are, of course, cautionary tales.
It is not uncommon for hopeful artists to dedicate years of their lives to training with an agency, only to never properly debut.
Some trainees just do not live up to expectations, says a staffer at a well-known agency (who asked for anonymity).
Instead of being dropped they will be tested out in different fields such as a variety show or TV presenting.
"If that doesn't work, it might be behind the scenes - styling, writing, choreography," says the staffer.
"Because the company has invested so much in to the training, they often refuse to let them go from their contracts until they have made some of the money back."
Ida Simmons began training with SM Entertainment, one of South Korea's other major talent agencies, at 14.
With a Korean mother and German father, her unique looks and note-perfect singing voice should have had her destined for big things with a company behind some of the top names in the industry.
But while her peers went on to the big stage, Simmons failed to catch the attention of new fans during focus groups and TV appearances.
Having signed a 13-year contract with SM, Simmons was technically benched by the agency and found a job by the company as a DJ on Korea's Arirang Radio to sit out the remainder of her contract.
"It was definitely difficult," Simmons, now 29 and free of her contract, has said.
"Now I'm just happy to be able to move on with my career."
Nevertheless, there is much the Western music industry is keen to learn from the well-oiled system in South Korea.
"The entire structure of developing a new artist in the US is completely different than it is in Korea," talent spotter Braun says.
"In Korea, there is no real distinction between management and the record company. They are one and the same and invest heavily in finding and grooming talent from a young age.
"I've actually learned a lot from YG and his company's system and really admire the work they do."
Over the next year, we could see more of Western music's big players looking for a slice of the K-pop pie.
Rapper Kanye West's creative team recently announced plans to launch Seoul-based joint-stock company 10-Jones, incorporating brand, agency and entertainment branches.
The Louis Vuitton Moet Hennessy group (LVMH) recently invested $80m in YG Entertainment.
As for CL - who will release a full solo album later this year - she has fan and personal friend, Chanel and Fendi creative director, Karl Lagerfeld rooting for her.
"CL is beautiful… you can't take your eyes off her. This year she will help K-pop take over the world."
About the author: Omid Scobie is the European Bureau Chief for US Weekly magazine and founder of Korean entertainment news site, IdolWow!