Nowadays, collection-based marketing programs have become the most commonly used tools for retailers to increase their revenue. This kind of program usually accidently triggers consumer collection behavior through a bottom-up process. However, previous researches usually focus on top-down process. In this study, we emply a 3 (possession level: two collectible rewards, one collectible reward and one noncollectible reward or two noncollectible rewards) * 2 (premium attribute: utilitarian vs. nonutilitarian) conditions for experiment to explore how collectible utilitarian attribute and initial possession level influence the ease of justification which motivates consumers to collect.