The advantage of a digital loyalty program is that you can send an offer to a specific group of customers rather than discounting across the board. Here's how to run a first promotion that doesn't cut into full-price sales.
Pick a goal before picking an offer
Decide what you're trying to change: bring back lapsed customers, fill a slow day, or increase spend per visit. Each of these needs a different offer and a different audience. Starting with the offer instead of the goal is the most common way a promotion ends up costing more than it earns.
Choose a narrow audience
For a first promotion, target lapsed customers only: people who visited several times and then stopped. This group is the easiest win, because they already know and like your business, and they're the customers you'd otherwise lose entirely.
Make the offer specific and time-bound
"20% off this Tuesday" outperforms "20% off anytime" because it creates a reason to act now and lets you steer traffic into a period you actually want busier. An open-ended offer mostly gets used on visits that would have happened anyway.
Send it as a push notification
Push notifications reach customers directly on the phone their loyalty card already lives on. Keep it to one sentence: the offer and the deadline. Anything longer gets skimmed past.
Measure against a normal week
After the promotion, compare visits from the targeted group against a typical week before it. The number that matters is whether those customers came back, not the total redemptions. Redemptions alone can't tell you whether you changed behaviour or just gave a discount to someone already walking in.
Once you've run one targeted promotion and measured it properly, the same pattern works for every campaign after it: narrow audience, specific offer, clear deadline, honest measurement.