Stamps and attendance

Each visit adds a stamp. When the customer completes the cycle you configured — ten visits, say — they earn one cycle, redeemable for whatever reward is priced in cycles.

The stamp goes in just by registering the visit, in the same action as the points. It is at most one per day: if the customer comes back in the afternoon, the points for that second purchase are added all the same and the screen tells you today’s stamp was already there. That is not a failure, it is the limit working.