Probably a scam, most of those survey and stuff sites are scams. If you google the name of the site with "real" or "legit" somewhere with the Search, you can find forum posts and such with other people like you asking the same problem.
trust me it is. they scam so does gaming lagoon (even through i got wii points from them one in the mail of course... and they e-mail the codes also you can't get anymore points and it's just not worth it...)
Ad clicking sites like bux however do work, but you have to spend like a year on the site everyday for a few hours for about $10.
I've actually gotten an NDS USB charger from Gaminglagoon. However I have filled out a ton of surveys and most have gotten declined.
I did get a 2GB SD card there once, but then my account got banned because my brother tried to make an account D;
OK after checking it out properly, I can tell you it's real but it takes so long to get anything it's probably not worth it.