Duolingo requires constant user attention and offers a gamified design in an attempt to get students coming back on their own. Oh, and it works on all the major mobile platforms, making it very broadly available: Unlike traditional classes, it doesn’t require specific locations, financial resources, and dedicated blocks of time.
Most importantly, though, this is a Luis von Ahn creation. That means the app is crowdsourced, and every tap is analyzed to help the student learn more quickly. Indeed, Duolingo says it employs a large team of machine-learning PhDs to analyze all the collected data to “craft adaptive courses that deliver tailored education for each student.”
At the end of the day, that’s likely the real reason Google Capital has made its latest investment; reCAPTCHA, von Ahn’s first startup, was sold to Google in 2009.