Had an idea for next gen narrowcasting: an intelligent mobile narrowcasting unit: a human being with a display.
Of course you can display all sorts of things on it;
Logos, advertisements, offers, slogans, guerrilla marketing stuff, sending smses to a certain number and have it displayed on the HNU.
You could also call this "Infiltration Narrowcasting" whereas this wil make it even narrower, considering people move in flocks and belong to groups that can be infiltrated with this-- its adaptability will make it a very strong form of marketing. A T-shirt remains 'passive'!
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The Siemens product is not a "must", of course. Other types of displays can be used, but this material triggered my idea.