The objective of this paper is to better understand the incentives and rewards structure in online serious games for crowds. We address the issue of feedback mechanisms with a focus on the relationship between game behavior and accumulated game scores (points). We posit that the score keeping system design is likely to inform us regarding patterns of participation in games. Our question is: what is the theoretical basis for designing a solid scoring function that would motivate players in three ways: a. to start playing; b. to continue playing; c. to strive to win? This paper presents a serious game for a large user base (crowd) and highlights some aspects and benefits of using an online serious game for crowds to enhance knowledge sharing. Understanding game scores promises to offer interesting implications in various fields such as business, knowledge sharing, game design, collaborative design environments and education. Currently, this paper is conceptual; however, findings are expected before the MCIS conference.