saw the google ad while surfing reddit
Google
Registration is not open atm but they let u know via email if leave your email

What's in it for you? Up to $25 in gift cards. Our panel management partner, Knowledge Networks, will give you a $5 Amazon.com Gift Card code instantly when you sign up and download the Google Screenwise browser extension.1 Then you’ll get additional $5 Amazon.com Gift Card codes every three months for staying with it.2 It's our way of saying "Thank you."
here's slickdeals thread Free $5-$25 Amazon Giftcard from Google - Slickdeals.net