Social media provide marketers interactive communication environments with opportunities to enhance existing relationships with consumers. Even though social media has been recognized as the most potentially powerful medium in business practice, there is lack of understanding in terms of why people use social media and how they perceive social media marketing messages. This study investigates (1) gratifications underlying social media usage, (2) attitudes toward social media marketing messages, and (3) the effectiveness of the messages concerning online shopping value. A research model was created based on the Uses and Gratifications theory. Social media gratifications, including entertainment, information and interaction, were examined as exogenous variables. Attitudes toward social media marketing messages and online shopping values were examined as endogenous variables. The results explain that attitudes toward social media marketing messages are strongly related to social media interaction and information gratifications, but are not related to entertainment gratification. Also, positive social media marketing messages increase online shoppers' hedonic values. As a managerial implication, marketers should provide useful information and an active interaction virtual arena using social media in order to create positive consumer marketing messages and increase online shopping value.