At Sunday’s Billboard Music Awards, the nominees for Top Social Artist included four names that needed no introduction: Justin Bieber, Selena Gomez, Ariana Grande and Shawn Mendes. But none of them walked home with the statue – instead, K-pop boy band BTS humbly and excitedly accepted the award. The Korean septet made up of Rap Monster, Jimin, Suga, J-Hope, Jin, V and Jungkook made their American red-carpet debut last night, but their BBMAs win was hardly their first major achievement. Get to know the social-media sensations and why they’re the international pop act to watch.

1. BTS write and produce socially conscious K-pop.
One look at Psy is proof enough that K-pop acts tend to focus on crafting crazy-catchy tracks with an eye toward the Western mainstream, but BTS (an acronym for the Korean term “Bangtan Songyeondan” or “bulletproof boy scouts” in English) stand out as an anomaly among their peers. While other K-pop acts focus on songs about heartbreak and partying, BTS have connected with audiences by touching on topics such as mental health (2015 album track “Whalien 52” tackles loneliness), politics (see member Rap Monster’s collaboration with Wale titled “Change”) and even female empowerment (“21st Century Girl” has been performed on Korean television). All the while, the members have writing credits on nearly all their songs and are taking on more production roles with later releases – also a rarity in K-pop. The 2016 single “Save Me” has members Rap Monster, Suga and J-Hope all credited as lyricists and producers.

2. They’ve sold out U.S. arenas.
Prior to this year, BTS had played small theaters on two different American tours, but their 2017 BTS Live Trilogy Episode III: The Wings Tour saw the band selling out arenas stateside. The tour was originally only set to include three U.S. shows at Newark’s Prudential Center, Chicago’s Allstate Arena and Anaheim’s Honda Center, but after tickets sold out within minutes, two more dates were added in Newark and Anaheim.

3. BTS are monster sellers around the world.
While BTS are a commercial behemoth in their native South Korea, with their 2016 album Wings being Korea’s best-selling album of the year, their sales are strong even in territories where fans don’t speak their language. In its first week, Wings moved 16,000 copies and charting at Number 26 on the Billboard 200, making it the highest-charting, best-selling K-pop album in America to date. The LP also debuted at Number 62 on the U.K. Albums Chart, and the recently released Japanese version of their Blood Sweat & Tears album topped the Japan Hot 100 chart with more than 200,000 copies sold.

4. The odds were stacked against them.
BTS were birthed in 2013 from BigHit Entertainment, a relatively small Korean record label and management agency that was mostly unknown until BTS broke out in 2015 with “I Need U,” their first Top 10 hit in their country. K-pop acts with some stateside success – like Psy, CL, Wonder Girls, BIGBANG and Girls’ Generation – all come from huge agencies like SM Entertainment, YG Entertainment and JYP Entertainment that have years’ worth of successful acts under their belts.

5. Their social media following is no joke.
Unusually, no member of BTS has an individual social-media account, but the strategy has led to huge numbers for their group accounts on Twitter (where 5.9 million followers currently see the members posting personal messages, selfies and playlists), Facebook (4.3 million), YouTube (3.9 million), Instagram (3.6 million), plus an additional 5 million on Korea’s popular V app where artists hold live-streaming broadcasts during which fans anywhere in the world can chat with the group. Their success on social media has seen them spend 31 weeks, so far, at Number One on Billboard‘s Social 50 chart, a global ranking of the most popular artists across online platforms, a feat that surely paved the way for last night’s win.