A research study was conducted to explore how joint branding affects consumer perceptions. Employing Young Rubicam s BrandAsset Valuator model and research tool, the study evaluated the joint branding potential of 10 target brands and 10 partner brands with 10 different partnership scenarios. The scenarios represented joint branding activities related to promotions, sponsorships, new-product extensions or licenses, and websites. In this experimental setting, the study findings suggested that brand alliances can help build brand equity, but only under certain conditions and in certain ways. Specifically, joint branding campaigns helped to increase a brand s perceived differentiation but also sometimes harmed perceived knowledge and esteem in the process. For our study, cause-related partnerships had the most uniformly positive joint branding program effects.