Apparently South Korea is not an attractive destination for English teachers, native course, but the Koreans like to learn a language from someone who speaks that language natively more Korean.
But Koreans also like the working day begins with sunrise and sunset, including work on Saturdays and Sundays let alone holidays.
That's why they decided to hire a teacher who cares not the long hours of class (at least not until the rise of robots in 2015)
Bot call Engkey and costs in a ten thousand dollars, in reality, the robot works as a kind of teleconference machine, where a screen with a qualified teacher on the other side.
