I'm sure I'm not the only one to do this, and at possibly the risk of ruining people's chances to get coupons like this from not only this thread, but future threads...
I guess my timing was lucky, but basically I've had the opportunity to just be sitting on my ass for the past few days.
I have this extension for Firefox that tells me when I get new email.
I subscribed to this thread and had CAG notify me via email, then I had my extension update me every 1 minute on whether I had new email.
So I got an email with the first reply since I last checked the thread. You won't get an email for each reply after that first new reply. Most of these emails were "Plz PM me a code." so I'd check the thread, delete the email, and move on.
Well I got lucky because after many emails, one was an actual code. (The first new reply is included in the email.) I copied the code directly from the email, and opened up a bookmark to my Amazon cart with Wii Sports Resort already sitting in it, with the ECA coupon already applied as well. I typed in my password to login to my cart, and pasted the code in, and got it.
So if you have the luxery of being able to sit at or work on a computer all day, you might be able to increase your chances by subscribing to the thread, having super fast new email notification, and having your Amazon cart ready to go.
I think there was a 4 minute delay between the post with the code and my final checkout on Amazon - which of course could easily be decimated by a lurker or something.
But I found my method greatly increased my chances as I had missed several code opportunities checking the site manually every so often. This method might be more frustrating now because it seems like the ratio of codes to 'can i have a code' posts is becoming less and less favorable.
Just thought I'd share. Perhaps someone has an even more effective method.