Gamified crowdsourcing: Conceptualization, literature review, and future agenda.

•A comprehensive review and future agenda of gamification in crowdsourcing.•Integrated conceptualization of gamified crowdsourcing systems.•Empirical results indicate that gamification is effective in crowdsourcing.•Differences in the use of gamification exist between different crowdsoucing types.•Practical recommendations provided for design of gamified crowdsourcing systems.