Which innovative retail technology was FIRST widely implemented in military exchanges before becoming common in civilian retail?

Post Exchanges (PX) and Base Exchanges (BX) have been crucial to military morale since their formal establishment. These retail operations serve military personnel and their families worldwide, offering tax-free shopping and generating billions in revenue annually. Beyond convenience, they represent a fascinating intersection of military history and retail innovation, adapting through wars and peacetime while evolving their marketing approaches and consumer psychology strategies.

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Barcode scanning systems (1974)
Self-checkout kiosks (1998)
RFID inventory tracking (2003)
Mobile payment systems (2011)