At first, even the people at Pabst — which has barely advertised for more than 20 years — were at a loss. But any trend with even the slightest commercial implications in the American marketplace immediately becomes subject to two iron laws. The first is that it will attract a swarm of consultants, marketers and journalists, trying to deduce the trend’s origins. Second, efforts will be made to amplify and prolong the trend, profitably.