E-liquids, cartridges, coils — consumables. A customer buys every 2 weeks, €15-25. Per year — €400-650. The only question: your shop or the competitor's.
Progressive cashback 3% → 5% → 7%. Push about new flavors, reminders to "change your coil." Referral program — the vape community is very loyal.
QR at the counter + staff who offer it = 15-20 new program members per day.