The stamp card for your burger joint.
No buzzer going missing. When burger number 42 is ready, the message goes to the phone.
This is what your card could look like

Your burger #42 is ready
Burger Thekla
How it works today
- The buzzer ends up in a jacket pocket and never comes back.
- The paper card is crumpled after the third visit.
- Anyone who forgot the card gets no stamp.
How it works with Thekla
- The message "Your burger #42 is ready" appears on the lock screen.
- One scan puts the stamp on the card in the wallet.
- An offer like "Today: free fries with your burger" reaches your guests directly.
Ideas for your reward
8 stamps for a free burger.
6 stamps for free fries.
10 stamps for a free meal.
These are just examples. You decide the number of stamps and the reward.