The casual game sector represents one of the fastest growing segments of the video game industry with successful business models. The Serious Games (SG) sector on the other hand is far behind with lower business benefits. This study explores how the casual game business models can be transposed into the SG sector, focusing on the freemium business model. We analyse the freemium business models in relation to four components: value proposition of the games, user’s segmentation, available distribution channels and revenue streams. After the theoretical analysis, the empirical analysis is completed through end-users survey (n = 237) and the analysis of three companies. Based on the end-users survey and the company analysis, the paper introduces key findings in relation to the four components of the free trial and freemium model and their transposition to the SG sector. Findings from the study include the opportunity to transpose the casual games freemium business model into the SG sector in order to allow the development of the SG sector through optimising their potential revenue streams.