To increase audience engagement and repeat usage, businesses can use to add game-playing aspects to apps and web services.

The word to fill in the space is "Gamification'.

Gamification is the use of game-design components and diversion standards in non-game contexts. Gamification ordinarily uses game-design elements which are utilized as a part of non-game contexts to enhance client engagement, organizational productivity, flow, crowdsourcing, employee enlistment and assessment, usability, convenience of systems, physical exercise, road violations, voter apathy, and that's just the beginning

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