Throughout most of 2018, the industry’s social media focus was on problems with Facebook and Twitter. Meanwhile, TikTok was quickly becoming the social media app for kids around the world.

Here’s 10 things you should know about TikTok right now:

#1 TikTok is an international version of the Chinese short-form video app Douyin. Users create 15-second videos set to popular music, or “act” along with famous snatches of dialogue from TV and movies. ByteDance merged TikTok with the U.S. lip-sync app Musical.ly—which it acquired in a 2017 deal valued at US$1 billion—in August, and the app has taken off since then. It now has half a billion monthly users.

#2 Parent company ByteDance recently surpassed Uber as the world’s largest privately backed startup, with a valuation of US$75 billion. It’s also using a recent influx of cash, courtesy of a US$3 billion funding round led by SoftBank, to aggressively grow its business in western markets. TikTok has both the financial clout and consumer momentum to become a major player in the social media space.

#3 TikTok is the fourth most downloaded iPhone app in the Canadian Apple app store in the photo and video app category, and the fourth most downloaded social app in the Google Play store, according to SensorTower.

#4 Worldwide downloads were up 20%, and monthly active users grew from 100 to 130 million in the wake of the merger with Musical.ly. In Canada, the download rate increased 24% after the merger. The app garnered 49 million worldwide downloads in December alone according to SensorTower.

#5 Perhaps the best indication of its rising power? Facebook launched a competitive app called Lasso in late 2018. Facebook has lost much of its cache with teens in recent years, and is clearly trying to remain relevant with younger audiences.

#6 Its North American popularity has been bolstered by celebrity endorsements such as talk show host Jimmy Fallon, whose #tumbleweedchallenge—in which people roll on the ground like a tumbleweed accompanied by western-themed music—has generated more than 23.9 million submissions. (PS: challenges are a really big deal on TikTok.)

#7 Despite its decidedly Gen Z focus, a recent Washington Post article noted that TikTok has also become popular among some professions, particularly nurses and firefighters. “Fall into one of those occupational niches on TikTok, and you’ll feel like you’ve stumbled into the The Ellen DeGeneres Show audience: an earnest, nonstop, normcore dance party,” wrote the Post, which suggested that TikTok’s popularity, at least in part, stems from the light-hearted nature of most of its content. But….

#8 …last month, Motherboard posted a piece headlined TikTok has a Nazi problem and, equally unsurprising, there are reports of sexual predators invading the space popular with young people and children. Horrible people ooze into every corner of the internet. This was inevitable.

#9 There are no real advertising opportunities for Canadian marketers yet, but it seems inevitable. Luke Bristow of social media agency The Honey Partnership, which works with TikTok, told The Drum: “TikTok has been successfully running ads in its Asian market for a while now, with ad formats such as brand takeovers, in-feed native videos and sponsored hashtag challenges.”

#10 And of course, there’s influencer marketing. According to Digiday, most influencer deals have been done between brands and creators directly, but that could change with TikTok working on deals with media agencies and companies. “We’re focused on consumer experience first, but we do have plans for that,” said TikTok’s head of global marketing, Stefan Heinrich.