I’m running a bakery retail business. I would to let my customer a temporary internet access while they are at my shop so I could provide a free internet access. I don’t have any idea at first until I realised that the Starbucks are using this method.
But I not sure how they do it:
Customers purchase a coffee or anything from the Starbucks, they grant the wifi access pin.
Next time when they come, they have to buy anything in order to get the new wifi access pin.