We'd booked our reservation for this pension along one of the southern coves of Geoje Island. It was a nice place and the owners were definitely reaping the benefits of having figured out Google Adwords before most others in Korea, because a lot of the other places in the area were empty but this one was full.
We'd generally prefer to just show up on-site and negotiate a room with a place based on the location and cost but we've also learned the hard way that this doesn't work well every time if everywhere is sold out.