Each code can only be redeemed once. If you want an invite and the codes are not working let me know and I will send you an invitation to your email address.
The Superpoints Network is a collection of sites where you can win and earn Superpoints that can be redeemed for great rewards. It's not just surveys. Everyday you can spin the wheel 30 times for a chance at points and you will win something. When someone signs up with your invitation or code you become their sponsor. Once you have two friends in your network you can start earning points based on your friends points as well.
You can redeem your points for gift cards, cash payout to Paypal, video game systems, and other electronics. It's pretty cool.