1. A computer-executable method for ranking content popularity in a content-centric network (CCN) content cache, the method comprising: receiving, by a CCN node, an interest in a piece of content stored in the content cache; servicing the interest by accessing the piece of content; updating a service rate associated with the piece of content; updating system-wide service rate statistics; and determining a popularity level associated with the piece of content based on the updated service rate and the updated system-wide service rate statistics.