Have you tried Swagbucks? In just about a month I've already earned 2 Amazon gift cards. I haven't done anything but searching just like I always do!
The search engine leaves a bit to be desired, but I honestly can't complain. I love gift cards and I love getting them for free.
Leave a comment if you have any question how it works. I'd be glad to help you.
Now go sign up! It's free!