Luis von Ahn: How to make learning as addictive as social media | TED Talk

I was impressed by his motivation to release Duolingo. He wanted to provide equal education for rich and poor alike. And he decided to provide the language education because it connects our salaries directory. So it's efficient.

If I have a chance to start my own business, I don't have to stick to the field I'm familiar with. Being logical is important.