You'll get every time the same card number, with said card being specific to the device. So they will be able to track that the same buyer is doing the purchase, which is what most POS-based analytics are interested in.

Way more important is the (sometimes filtered) dump of everything on your bill that is passed on to various corporations (Nielsen, sometimes direct to suppliers), and how in-store analytics then build data at neighbourhood or per-store level.

Store analytics need not know that specifically "WirelessGigabit" bought something, store analytics is more interested in "we have repeated customers with such and such spending and purchases" and "in this zip code we have this kind of population with associated types of buyers" and "This is how much people are buying certain products and when, so that suppliers can plan campaigns and production"