Gamification
Gamification applies game elements (points, badges, rankings, challenges, rewards) to non-game domains. QR codes are widely used for implementation - digital stamp rallies where scanning QR codes at locations collects stamps for prizes, treasure hunts with hidden QR codes, and educational quizzes triggered by textbook QR codes.
Key design principle: game elements are means, not ends. The value lies in the behavior the game promotes (exploring shops, learning, healthy habits), not in collecting stamps itself.