Which retail innovation was first widely implemented in military exchanges (PX/BX) in the 1980s, decades before becoming common in civilian retail?

Military post exchanges (PX) and base exchanges have evolved dramatically since their inception, becoming sophisticated retail operations serving military personnel worldwide. These unique retail environments blend patriotism with practicality and have pioneered several retail innovations that later spread to civilian markets. This trivia question explores a groundbreaking retail innovation that originated in military exchanges and changed how service members shop on bases around the world.

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

Biometric payment systems using fingerprint recognition
RFID inventory tracking for merchandise security
Star Card - the first military-specific store credit card with loyalty rewards
Self-checkout kiosks with barcode scanning