A week or so ago, I received a random survey request in the mail. I usually just recycle them (probably like many people, but I don't want to presume), but something made me open it. I'm glad I did, because inside sat a very new, crisp $2 bill. I have received nickels in surveys in the past, but I definitely prefer a crisp $2 bill. So, open those surveys, you never know what may be waiting inside. I'll leave it to your imaginations whether the $2 bill actually incentivized me to fill out the survey.
Was it Neilson? I've always wanted to be a Neilson family. I got an invite once and did the survey and got a gift card or something but it didn't go further. Unfortunately.