During the Super Bowl on Sunday, the language learning company spent a crazy amount of money on a five-second ad featuring Duolingo’s new booty. The clip featured Duo’s BBL expanding and then ...

Language-learning app Duolingo makes around $500 million annually, despite offering all of its lessons for free. WSJ explores how the company is using AI and A/B testing to keep users hooked.

Duolingo successfully motivates its users to persevere with language learning, which is why its user trends are soaring. Most of the company's revenue is from paying subscribers, and it seems many ...