Kylie Jenner is on the cover of another magazine, but this time it's highlighting her brains over beauty. In the latest issue of Forbes, the magazine says 20-year-old Jenner is currently worth $900 million, which would soon make her the youngest self-made billionaire in history. Her Kylie Cosmetics line has reportedly raked in $630 million in sales in three years, and Jenner owns 100% of the business. She tells Forbes that she credits her success to social media, where she has amassed 110-million followers on Instagram. Mark Zuckerberg holds the record for youngest billionaire at age 23, but Jenner will likely reach the milestone at 21.