The confluence of Big Data analytics and digital media is rapidly transforming the retail and grocery marketplace, fundamentally altering how food companies engage with consumers and how families make nutrition choices. This model of food marketing could exacerbate existing health disparities, especially in areas where youth are at higher risk for obesity, and where the choices for healthy foods are limited, but it also creates opportunities for harnessing digitally-driven Big Data as a positive force for health. The primary purpose of this study is to determine the key research questions public health researchers need to investigate to understand the public health implications of “path-to-purchase” and retail food and beverage marketing. The research will be qualitative in nature, relying on published data from a variety of sources; consultation with public health researchers, practitioners, and legal scholars; and interviews with representatives of major retail chains, food companies, and data analytics firms. Findings will help to inform public health scholars of the nature and extent of the transformation of the retail setting, and help researchers construct the studies needed to assess, and respond to, this new landscape.