I always use ebates. Also signed up for daily emails for "double cah back" of the day. Each day one online site has double percentage cash back. I also check "retail me not" sit before I log on to ebates as I often can get a code for free shipping that will work with ebates. It has been my experience that once you are in ebates, don't wander from the site as the rebate will not process. You can open another window to check another site however and then return to ebates. (Hope I explained that correctly). I find myself waiting for "double cash back" day on some purchases, such as ink, as some sites repeat DCB quite frequently.