Ebates has a one week promotion with increased cashback at certain stores online. They are offering a rate of 15% cashback on 400+ stores. You can see the full list of stores here.
If you do not have an account you can use my referral link to sign up and get a $10 bonus when you make minimum qualifying purchases totaling at least twenty-five dollars ($25) within ninety (90) days.
15% is a pretty good rate and it should give your the best offer on a few merchants. Still make sure to compare rates to other sites.