If you have been ever to Korea and have made choices for some prepaid SIM services for foreigners in the past 3 years, I guess that you may have heard the SIM card which is called “EG mobile”. It is the name of the company, that started prepaid SIM business for foreigners about 3 years ago, in 2013. It concentrated on the sales in shops around Incheon Int’l Airport, Korean convenience store GS25, (in offline) and internet open market shop (in online).
At that time, there were no competitors in the market and the contents they provide was reasonable to the price. It was so small company that it didn’t worry about Korean government regulation which was not determined at that time (what condition must legally be fulfilled to activate the prepaid SIM for travelers… and so on), and invested aggressively in marketing their products whereas the potential competitors hesitated to enter the business worrying the uncertainty in policy and waited for the decision regarding the market regulation. Sometimes it was recklessly too brave to offend the government. Anyway, as the result, it became the name of prepaid SIM in Korea, itself. It’s the reason why you encounter the name so often in Google search results about prepaid SIM in Korea.
But as time went by, the direction of government regulation became somewhat concrete. At last, the subsidiary company of “kt” (korea telecom; the no. 1 telecommunication company who has the most subscribers in S. Korea), “kt Mmobile” began to play in the market and to take up the position in 2015. They have supplied their kt Mmobile SIM card for travelers to the Korean major 2 convenience stores, the Seven-Eleven(7-11) and CU since then and opened internet shopping site, krsim.net, too. Finally, travelers have become to enjoy the trustful services that the Korean top telecommunication company provides.
On 1st. March, 2016. GS25 came to be out from the Arrival floor in Incheon Int’l Airport and EG mobile lost the place to sell their products there. Now the Airport has only three CU convenience store there, so kt Mmobile SIM card comes to be the most dominant and popular prepaid SIM card for traveler in S. Korea, now.