Although iTutorGroup has turned into one of the largest online marketplaces of learning in the world, earning itself a $1 billion valuation along the way, the company can trace its roots back to the pre-internet age, when English tutoring was restricted to face-to-face interaction.

When CEO Dr. Eric Yang first got into the education sector in the early 1990s, he would create a list of characteristics for each English learner in order to personalize the material.

Taking his customization to the next level, Dr. Yang would go on to successfully launch an online English service in China in 2004, bringing his uniquely crafted lessons into the digital age.