It all depends on where you are in life’s great food chain. If you’re in that middle section that uses a lot of the main brands (Kraft, Betty Crocker, Pillsbury) coupons are great, because they’re the big coupon printers and that’s the stuff you buy anyway. I’ve been right through the chain, used to be too poor for that stuff even with coupons so they were useless to me, then I made enough to change to those brands and used coupons a lot, now I’ve moved past those to the Boar’s Head section of the grocery store and they don’t make coupons so I no longer use them.
Ahem! Ever hear of $5 off $30 coupons? You can use those for anything except alcohol and tobacco. Otherwise it doesn't matter what you buy. You get five bucks taken off your purchase.