Thanks! A shame the site didn't help you, but I am not sure I agree that the good ones need to be found themselves and don't advertise. In my experience it was opposite, the better ones were more likely to understand the importance of marketing. I think I have most of the better goshiwons in Seoul on the site, I can only think of 1 or maybe 2 goshiwons that considered themselves too good to need to advertise.