On a recent American Pickers episode they talked about how advertising added a lot of value to a sign, clothes, etc. If something had advertising on it was worth a lot more than if it didn't. Why would that be? I also noticed how advertising has been with us a long time. It's no new. All sorts of little advertising baubles were used for marketing.
It's important as a hook for historical narrative, with that tag (whether literal or not) it's easy to start a conversation. Businesses and people come and go, but objects with advertising give you little hints at some interesting matter that may no longer exist. - OCoG of FF, Jimminy