In 1873, the retailer Montgomery Ward was just a year old, and the first Sears Roebuck catalogue was still 20 years away. Together, these companies invented mail order as the “killer app” of the railroad age, creating a continental market for consumer goods, with all of the economies of scale that followed.
1873年，零售商蒙哥马利·沃德才仅仅创建1年，而西尔斯·罗巴克的第一份商品目录还要等20年后才出现。而正是这些公司一起发明了邮购——它成为了铁路时代的“杀手级应用”，为日常消费品创造了一个横跨整个大陆的市场，其他所有的规模范畴也随之兴起。