Which chip suits a tag that many people will tap?
Reading wears nothing, so the heavy use that worries people has no effect on the chip. What matters for a public tag is the widest possible compatibility, which means Type 2, and password protection only if the content must stay changeable.
Heavy reading is not wear
A tag tapped a thousand times a day is electrically unchanged. Reads do not modify memory, so no write cycle budget is consumed and no degradation occurs.
This removes the intuition most people bring to a public deployment, which is that a busy tag needs a tougher chip. It does not. It needs a tougher tag, which is a different component.
Compatibility is the real requirement
A public tag is tapped by phones you did not choose, including old ones. Compatibility is therefore the property that decides whether the deployment works or half works.
Type 2, without qualification. It is read by essentially every phone with NFC hardware and it removes the entire class of failure where a tag works for some visitors and not others.
Choosing anything else for a public tag needs a specific reason and accepts a specific exposure.
Protection, if the content must change
A public tag can be rewritten by anyone with a phone, which is a real threat with a printed equivalent that occurs regularly.
If the content is a stable redirect address, lock the tags and the threat is closed with no chip requirement. If the content genuinely must remain changeable, a password protected chip is the mechanism, and that becomes a purchase decision.
Most public deployments can use the first route, which is why password support is needed less often than it is bought.
The specification that actually matters
For a public tag, the chip is a small part of the decision and the physical product is nearly all of it.
A substrate that survives weather, cleaning and handling. An adhesive rated for the actual surface and the actual temperature range. A construction that resists being peeled, or a tamper evident one that stops working if it is. An antenna large enough that a tap works first time for someone who has never done it before.
Those four decide whether a public deployment is still working in two years. The chip reference, provided it is a compliant Type 2, decides almost nothing.
Frequently asked questions
Will a busy tag wear out faster?
Not from reading, which is what busy means here. It will wear from weather, cleaning and handling, all of which are properties of the tag rather than the chip.
Should public tags be locked?
Usually yes, once the content is stable and verified. Writing a redirect address first makes locking free, since the tag then holds something that never needs to change.
Is a tamper evident tag worth it in public?
Where removal or substitution is a genuine concern, yes. Those tags break their antenna when peeled, so a removed tag stops working rather than being reusable elsewhere.
Does a public tag need more memory?
No, and usually less. A public tag should hold a short redirect address, which is the smallest useful content there is.