Born into poverty, Kim, 49, paid his way through university by giving private tuition and skipping meals. The trained industrial engineer quit his job at Samsung in 1998 to set up online gaming companies Hangame and NHH. Riding on the smartphone revolution, he founded free messaging service KakaoTalk in 2010, and quickly added platform- specific, revenue-generating games and apps. KakaoTalk merged with internet company Daum Communications last year to become Daum Kakao with a US$9.5-billion valuation. It currently controls 90 percent of the Korean market.
Net worth:US$2.6 billion