I've written many times before of my love for cashback services, which pay you back a percentage of your purchase just for going through their shopping portals.
For example, FatWallet recently started offering 3 percent back on Amazon Instant Video and MP3 purchases. And Ebates is currently paying 4 percent to 5 percent back on purchases from Dell, HP, and Lenovo.
Of course, there are lots of cashback sites out there, and some offer bigger bonuses than others. How can you make sure you're getting the maximum rebate for each store you visit?