A product display surface supports at least one product being offered for sale thereon. This product display surface has a weight-sensitive RFID tag associated therewith. This tag has at least one transmission element that moves with respect to a remaining portion of the tag as a function of weight being supported by the product display surface. So configured, the weight-sensitive RFID tag transmits at a first level when there are no products (or only a few products) on the product display surface and at a second level when there are at least a predetermined number of products on the product display surface, the first transmission level being less than the second transmission level. An RFID-tag reader reads the weight-sensitive RFID tag and a control circuit determines when the first product display surface lacks sufficient displayed inventory as a function, at least in part, of the weight-sensitive RFID tag's transmission strength.