Sharing is the most common behavior in the world, and it happens any time and everywhere, especially via purchase. People often purchase products not only for themselves, but sharing with others. However, most of the prior research on purchasing behavior only focus on self-use or gift-giving. Thus, this study aims to research on the relation between sales promotion and purchase intention, and to explore how the condition of self-use and sharing may affect the preference for a price discount or a bonus pack. Four experiments are used in this study. In Study 1 and 2, we keep price and quantity constant across two conditions, and to test whether people prefer a price discount or a bonus pack under sharing condition and self-use condition. The results approve that when under self-use condition rather than sharing condition, people significantly prefer a price discount, because they are concerned for reducing losses (price discount are framed as reduced losses) instead of less quantity. Further, Study 3, which is extended from the former studies, aims to research on the influence of intimacy on the decision among different types of promotional offers. The findings show that people are more willing to choose a bonus pack when they purchase to share with closer individuals because of different levels of responsibility. Furthermore, we use Study 4 to test how the consciousness of responsibility towards whom they share possibly influence the preference for a price discount or a bonus pack. The results suggest that when under the self-use condition, people show the strongest preference for a price discount, due to little consciousness of responsibility for anyone. By contrast, when people have more consciousness of responsibility for whom they share, they show stronger preference for a bonus pack, which could benefit both others and themselves. The results suggest people show the strongest preference for a price discount under self-use with low responsibility. However, when people feel more responsible, they may show higher preference for a bonus pack which could benefit others and self. To conclude, different preference for a price discount or a bonus pack is significant under sharing and self-use conditions, and responsibility has the mediating influence.