Given the enormous growth and significant impacts of group buying on Internet business marketplaces, understanding what motivates consumer online group buying (OGB) behavior is crucial. Drawing from Uses and Gratifications (U&G) perspective, this study investigates consumers’ motivations for using OGB. The laddering interview technique is used to interview 52 online group buyers and to capture the various needs they are seeking to gratify through OGB behavior, with grounded theory used to determine motivation categories. In total 16 motivations were identified from data analysis. The findings suggest that consumers are motivated by various factors to use OGB. Additionally, it is found that there are a few different motivations in OGB context compared to other e-business model contexts. This study has the potential to make significant theoretical contributions to IS discipline and e-business regarding consumer OGB behavior. Moreover, the results can benefit both OGB vendors and suppliers planning to promote their sales through OGB.