I had an American friend, Peter, who worked in Ilsan. He's back in the US, now, but one time when I was hanging out with him and the TV was on, and this commercial came on. One of those ubiquitous, twitchy, obnoxious TV commercials. Peter and I had been talking, rather seriously, about the positives and negatives of "life in Korea," and when that ad came on, Peter said, in a wry tone, "If it weren't for that ad, I would love this country."
That ad still comes on the TV all the time, half a year later. And it came on, and I remembered Peter's joke, and laughed. And just to give everyone a taste of something small and irrelevant but absolutely, undeniably a part of "life in Korea," here is that ad. Enjoy! Or throw things at me! Whichever.
I think 원캐싱 (won-kae-sing i.e. "won cashing") is a check-cashing or salary-advance type service. As if you could tell from the ad – although note the exhorbitant interest rate that flashes up in the fine print at one point.