Feeney - who also boasts roughly 5 million followers on Snapchat competitor TikTok - says she delved into Spotlight in November to connect with a new audience. "I started posting a ton of stories about my daily life, funny videos with my friends or boyfriend, unboxing new beauty or kitchen products I wanted to try," she says.

Katie Feeney, 18, a high school senior in Olney, Md., said she has earned over $1 million from Snapchat in the past two months by posting unboxing videos and funny content (in one clip, she spins on a hoverboard while seamlessly appearing in new outfits). Ms. Feeney said the cash has opened up new opportunities already. Colleges that she wasn't planning to apply to because of financial concerns are suddenly on the table.

TikTok has become a democratized tool, both for users and brands to create content but also to become part of an ongoing dialogue and discussion, says Brian Mandler, co-founder of The Network Effect, a digital agency focused on short-form content. "What we've learned very quickly is that instead of just liking and engaging with posts, people who are active on these platforms really have a voice."

TikTok has "more than 100 million" monthly active users across Europe, according to a blog post by Rich Waterworth, the company's European general manager.

In an exclusive interview with Business Insider on Sunday, Waterworth said user numbers had "been growing really well for a long time."

…TikTok will continue to be applicable – and just as important – in the future. In that sense, it matters less whether TikTok itself survives or not, explains Brian Nelson, the co-founder of The Network Effect, and more that “we’re actually witnessing the birth of a format.”