Just bought 2 World of Goo codes. The entire process took less than 10 minutes as I just PM'd what I wanted, he gave me his paypal address, I sent the money and a minute later I got the codes via PM. You go to the Wii Shop Channel to the section that let's you redeem codes and World of Goo comes up when you plug in the code.
Fantastic deal. Friendly and super fast seller. Can't recommend enough. To anyone wanting World of Goo for the Wii, jump on this deal as it's almost half off the regular price. Enjoy!