Here's a pie-in-the-sky example: I almost always buy clothes in-person. I want to see what I'm getting, and want to avoid the issues (discussed in other, mostly Amazon-related, posts) that come from buying stuff online. But I often run into trouble finding the specific item (make, style, and size) on the shelf. If each item were tagged (possibly as part of the anti-theft tag), I could be led directly to where the item is.
Here's a more realistic example: I want to buy an DB9 null-modem adapter from Micro Center. I can find out in general where it is. But if a tag were attached to the shelf, I could be led directly to where the item should be.
Of course, there are tons of issues (among which cost is but one). But it's nice to know that things like this may be possible!