It is actually very common in Indonesia, has been seeing it since 2013, in Singapore too! I'm surprised Korea only get into this selfie pod much later cuz I know that the Koreans love to take selca.
Last June 2014, I actually brought one when me and my friends were travelling around Seoul. I used it to took some photos on Namsan tower and a lot of the Koreans looked amazed. There's this lady who actually came to me and spoke in Korean saying that "wow your selca idea is good", which made us laughed really hard cuz it is already very common in Indonesia and Singapore.