Just noticed the upsized cashback on ShopBack and the coupon "UNKNOWN" listed on their site as well.
"Up to" 20% cashback capped at $25
"Up to" 30% off sitewide capped at $40 on 5 local, travel and shopping deals. Exclusions may apply.
Sitewide deal is today only, as part of their Red Wednesday deal.
I am assuming these are usable together, but with ShopBack, fingers crossed.