There are many types of promotional activity, but it doesn’t have to be about offers & discounts. Have you considered using loyalty points as an incentive?
Offering loyalty points for a period can help to engage & draw attention to the promotional period. For example, you might have a quiet day or week, or want to promote an event or season?
It’s a great way to give back to customers and create engagement. And it’s an economical option too, a revenue generator even, as any points gained will be redeemed on future visits & sales.
You could offer ‘double points’, ‘bonus points’, or points-based for criteria, such as tied to a product purchase.