If you have Staples Rewards check your "coupon wallet" by logging into your Rewards acct online. I’ve had a $10 off $10 coupon (and a $20 off $75 coupon) two months in a row now. Honestly if i didn’t check the coupon wallet i would never have known they even sent it to me. As always YMMV.
https://rewards.staples.com/SRC/CouponWallet.do