Personality traits1 have long been shown to contribute to consumer behaviors. Besides the main effect of personality, it seems also plausible that other factors may impact this relationship. To understand such situational effects, in this study we analyze two possible variables, namely, income and needs. We conduct extensive analysis on a large industry dataset across over 100 product categories. For each category, we build a prediction model for consumption decision based on the derived personality features. We experiment with our prediction models under different conditions segmented by both situational factors. Our results suggest that personality's decisive power on consumer behavior varies significantly among different income levels, but non-significantly between consumer needs. Together, income and needs also have significant effect on the association between individual's personality and consumption behavior. We conclude this work by discussing the implications of our experiments and how our finding can benefit the design of more personalized recommender systems in real-world settings.