If you ask to other koreans about messenger that they are using now, most of people answer that they are using Kakaotalk. I can say that everyone who have = has smartphone use Kakaotalk to communicate with other people in Korea. This application was developed in the early time we experienced smartphone. At that time, we has = had trouble with telecommunication company about the high fee for sending messages. The man who developed this service thought that he can serve free service to people if he use mobile application platform. He focused on this free service and this really worked. Now this application have been used not only in Korea but also in a lot of other countries. The point of this case is that he thoughtfully cared about user's = users' demand and found other way to make a benefit while maintaing = maintaining free service. This behavior gave Kakao company power and made them so big company that they merge a big internet service company. Now Kakao cooperation is getting bigger continuously and he who first made this service become the main character in myth of foundation story.