The smart shelf for shops demonstrates how item level tagging can be beneficial for both stock taking reasons (the inventory is kept up-to-date in real time) and for the customer.
When an item is removed from the shelf the warehouse is immediately notified, allowing a prompt replenishment or an immediate generation of an order to the supplier. From the customer point of view, the shelf is always full, and if an item is out of stock the customer gets notified. In particular, this system takes into account the possibly long delay from the time an item is picked up from the shelf to the time it is paid for.