Did you know you can make a few dollars submitting receipts for things you're already buying anyways?
ReceiptHog and ReceiptPal are two of my favorites, you can use just about any receipt, and don't need to buy a specific product to get points toward rewards.
Yaarlo is similar and fairly new. Snap your receipts to get a % back on every purchase. Use my code CHRISTIN575 to earn more! I've cashed out $20 in less than a month with this one already. Very nice!
To use these you'll need to buy a specific product for a rebate. Ibotta recently started offering a wide variety of 'any brand' rebates which are good for milk, bread, fruits and vegetables, things you're most likely buying anyways. CheckOut51 offers a fruit or vegetable rebate each week also.
Cash back on all your online purchases. They scan your inbox for items, track price drops and automatically apply for your rebate! Set it and forget it.