1. A method for merging face clusters, the method comprising: with a physical computing system, analyzing a set of digital images; with said physical computing system, grouping instances of faces within said set of digital images into a set of face clusters, each of said face clusters corresponding to a particular person; and with said physical computing system, determining a probability that a person associated with a first face cluster from said set of face clusters is the same person associated with a second face cluster of said set of face clusters; wherein said probability is based on both a social similarity between said first face cluster and said second face cluster and a facial similarity between said first face cluster and said second face cluster.