Most freebies require at a minimum that you provide your name and address. These surveys are powered by Opinion Network. It doesn't sound too good to be true either but for some reason, you still feel funny about it.
Opinion Network is a third-party survey company that lets people use their surveys on their site. If you see this information required for a freebie then this freebie is probably a scam. It seems like freebie scams are all over the Internet these days.
File a Complaint. It will keep your information safe and secure.