In case anyone's interested, here are the results of my latest round.
Codes Purchased: 58
Cost: $18
Winning Codes: 29
Win Percentage: 50%
Resulting Wii Points: 5,800 ($58)
Cost per 100 Wii Points: $0.31
Not as great as it once was, but I'm still ahead of the curve.

FYI, I tried gaming the system to see if it had any effect on win percentage. As far as I can tell, it doesn't. I entered these codes over the period of 3 days--all in the morning--with several minute between each play session. It didn't seem to affect the likelihood of winning.
Has anyone tried to play late at night? I wonder--for example--if less than 5,000 songs were given out that day they'd just start handing them out like candy before the day reset.
I just purchased another 53 more. We'll see how it goes.
