My referral code:
What is/How to:
HitPredictor is a music survey site where you can earn $5 Amazon gift cards for rating music. They have weekly invitations to rate songs for Amazon cards. Sometimes it is a guaranteed $5 AGC for rating 10 songs (10-15 min). Sometimes it is an invite to enter a raffle of $25 AGCs for rating songs.
There is also a prize store, but you will only get the gift cards from the email invitations. Make sure you Opt-In to the email notifications and if you are invited to join a 'Music Panel', say YES.
Sign up with promo code VIP for some bonus points. Can use them to enter more gift card raffles in prize store.
You need an email address to sign up. Must be 13 or older. Must be in US. (b/c rating songs for US radio)
There is a screening process where you will be asked about radio station and music genre preference, but if you don't hate radio you should be okay.
Once you sign up you should get some sort of email invite (guarantee/first50win/raffle/etc.). Click the link. Rate the songs. Will get gift cards in less than a week. If it's a raffle you'll know if you won in less than a week.