Almost every grocery chain now runs a loyalty programme, and most shoppers join all of them without thinking. But the programmes are not equal: one pays you in fuel discounts, another in digital coupons, a third in personalised prices that only appear if you check the app before you shop. The difference between the best and the worst programme for your household can be hundreds of dollars a year, and the winner depends on where you shop and how you shop.

Kroger's programme is the most generous for frequent shoppers. Members earn one fuel point for every dollar spent, and 100 points save 10 cents per gallon at Kroger fuel centres, up to 35 gallons. Digital coupons stack on top of the fuel points, and the weekly deals are personalised based on your purchase history. A household spending 150 dollars a week can realistically save 30 to 50 dollars a month in fuel and coupons combined, which is the highest headline value of any major programme.

Safeway's programme works on a similar model, with rewards points that convert to grocery discounts or fuel savings, plus personalised digital coupons. The key difference is the reward choice: you can spend points on groceries instead of fuel, which suits households without a car or without a nearby Safeway fuel station. The app's just-for-you prices are genuinely personalised, and checking them before a shop is worth a few dollars every trip.

Stop and Shop, Giant and other regional chains run programmes built around digital coupons and weekly bonus offers. The savings are real but smaller, typically 10 to 25 dollars a month for a regular shopper, and the programmes reward app users far more than card-only members. If you never open the app, you are leaving most of the value on the table, because the best coupons are digital-only and expire weekly.

The discount chains play a different game. Aldi has no loyalty programme at all and competes on everyday low prices, which often beats a loyalty programme's savings for a small household. Walmart's programme is built around Walmart Plus rather than a free loyalty card, and the value depends on whether you use the delivery and fuel benefits enough to cover the subscription. Lidl's programme offers weekly coupons and a birthday reward, and it is free, so there is no reason not to join if you shop there.

To compare programmes fairly, track one month of real savings. Write down what you spent, what you saved in coupons, and what you saved in fuel, for each store you use. Then divide the savings by the spend to get your real rate. Most shoppers find one programme earns 3 to 5% back and the rest earn under 1%, usually because they shop at the second store rarely or never open its app. The programme that wins is the one at the store you already visit most, with the app you actually check.

The stacking rule still applies: loyalty programme plus digital coupons plus a cashback credit card plus a receipt app is four layers on one shop, and the loyalty programme is the base layer that makes the rest work. Join the programme at your main store, check the app before every shop, and treat the other programmes as occasional bonuses rather than a second job.

Manufacturer coupons stack with store loyalty discounts, and the combination is where the real savings hide. A store coupon for 1 dollar off plus a manufacturer coupon for 1 dollar off on the same item is 2 dollars saved, and some stores double manufacturer coupons up to a limit. Digital coupons in the loyalty app are usually store coupons, so check whether a manufacturer coupon exists for the same product before checkout. The best weeks are when a sale price, a store coupon and a manufacturer coupon all apply to one item, and the total saving can reach half the shelf price or more.