Ersatz Utility, Popular Demand, Herd Instinct

Herd instinct often stimulates someone to assimilate themselves to the crowd, simply for the sake of blending in.  In Economic activity, that instinct is frequently manifest in a consumer's wish to conform in response to a perceived 'popular demand' for an otherwise useless product, thereby generating apparently freely calculated Ersatz Utility.  But consumers are not the only ones susceptible to such deception.  Just as mystified by Ersatz Utility are Economists who conflate it with real usefulness, or who associate what is unarguably a powerful marketing ploy with the Demand side of exchanges.