Duke’s full-credit course — officially called “Building Global Audiences,” but better known as “the TikTok class” — teaches undergrads at the Durham, North Carolina, campus how to optimize their presence on social media apps. Over the semester, students in professor Aaron Dinin’s class have collectively gained 145,000 followers and garnered 80 million views for videos they produced.

Natalia Hauser, a sophomore in the class, has roughly 227,000 followers, with about 12,000 gained during the semester. Her TikTok account (@natisstyle) helps her generate anywhere from $1,000 to $7,000 a month through partnerships with brands like Barnes & Noble, Macy’s, Canon and Pepsi. Sometimes, she can make as much as a $5,000 for a single post.

Data from research firm Statista show the global influencer economy has more than doubled since 2019 and was worth a record $13.8 billion in 2021. Of course, most TikTok users make nothing at all from their posts, and those looking to partner with brands often struggle to make more than a couple hundred dollars here and there.

For some, the math is obvious. Mark Setlock (@financeunfolded) was a dual major in finance and accounting at the University of Michigan, and had plans to work as an investment banker on Wall Street.

He launched Finance Unfolded on TikTok in January 2021, and Setlock says it gained 60,000 followers within the first month. He received his first paid offer to make a 30-second video for $300 in March. By December, he was raking in $40,000 a month, and he decided to drop out of college after just three semesters to pursue influencing full-time. Now, the 19-year-old says he’s signing six-figure sponsorship deals.