Can one tag serve several products?
It can, by pointing at a page listing them, and relevance falls fast with each product added. A tag serving one item answers the question someone actually has. A tag serving a category answers nobody in particular and gets used accordingly.
How it works
The tag holds one address, and that address leads to a page listing the products it covers. The visitor chooses.
There is no way for the tag to know which product the person was looking at, since it is a passive object with one piece of content.
So sharing a tag always means adding a step where the person selects, and every step costs some proportion of them.
Why relevance falls
A tap is worth taking because it answers a specific question quickly. A list of eight products replaces that answer with a menu.
The person now has to find their item, which they could have done with a search, which is what they were avoiding by tapping.
The signage suffers too. A sign for one product can say what you get. A sign for a category can only say more information.
And measurement suffers, since arrivals tell you the shelf was used rather than which product prompted it.
When sharing is right
When the products genuinely share the answer. A size guide covering a whole range, a care instruction for one material, a delivery policy.
When the alternative is no tag at all, because per item tagging is not affordable at that stage.
When the display is the unit rather than the product, such as a promotional stand where the campaign is the subject.
In all three the tag is honestly about the group, and the signage can say so.
Doing it per item instead
The cost of per item tagging is lower than it looks, because the tags are cents and the expensive part is encoding.
A chip that mirrors its own identifier removes that expense entirely: every tag is written identically, and your server resolves each one to the right product.
That turns a per item project into a single write plus a mapping table, which is the difference between a pilot and a rollout.
Start with the products that generate questions rather than the whole range. A dozen tags at the items people actually ask about is a better first deployment than five hundred everywhere.
Frequently asked questions
Can a tag detect which product I am holding?
No. A tag is passive and holds one piece of content, so it cannot know anything about its surroundings.
Is a category page acceptable?
Where the products genuinely share the answer, yes, and the signage should say so. Where they do not, the menu costs you most of the value.
Is per item tagging expensive?
The tags are cents and the encoding is the cost. A chip that mirrors its identifier removes that, since every tag is written identically.
How many products should one tag cover?
As few as possible, and ideally one. Each addition makes the promise on the sign vaguer.