Globally, users are sharing content on social networking sites (SNS) to signal their preferences and to build a positive online reputation. Using the approach and avoidance motivation theory, we examine the relationship among online impression, guilt and valence of shared content on SNS. Two experiments were conducted to test the conceptual model. The findings indicate that people prefer sharing positive content over negative content. Also, negative content induces guilt and affects the online impression and motivations to achieve desired goals. Therefore, social media marketers can use distinct valence of content to help consumers to achieve their goals effectively, especially in the fields of health care and education. The results suggest that avoidance motivation is more effective than approach motivation for achieving the goal of a positive online image.