A computer-implemented method operable on a server in a content delivery, CD, network, wherein said CD network distributes content on behalf of one or more subscribers, the method comprising, at said server: in response to a request from a client for a particular resource, if said particular resource is already in a cache on said server, serving said particular resource to said client from said cache; otherwise if said particular resource is not already cached on said server, determining whether a count value associated with said particular resource exceeds a first threshold value, and, based on said determining, when said count value exceeds said first threshold value, obtaining said particular resource from another server (104, 106); caching said particular resource obtained in in said cache regardless of the amount of free space in said cache; and serving said particular resource obtained in to said client; and, based on said determining in, when said count value is determined to be less than a second threshold value, obtaining said particular resource from another server (104, 106); and serving said particular resource obtained in to said client, wherein said particular resource is not cached in said cache when said count value is determined to be less than said second threshold value; and, when said count value is determined to be: (i) not less than said second threshold value, and (ii) not greater than said first threshold value, then obtaining said particular resource from another server (104, 106); selectively caching said particular resource in said cache when the amount of free space in said cache exceeds a third threshold; and serving said particular resource obtained in to said client. if said particular resource is already in a cache on said server, serving said particular resource to said client from said cache; otherwise if said particular resource is not already cached on said server, determining whether a count value associated with said particular resource exceeds a first threshold value, and, based on said determining, when said count value exceeds said first threshold value, obtaining said particular resource from another server (104, 106); caching said particular resource obtained in in said cache regardless of the amount of free space in said cache; and serving said particular resource obtained in to said client; and, based on said determining in, when said count value is determined to be less than a second threshold value, obtaining said particular resource from another server (104, 106); and serving said particular resource obtained in to said client, wherein said particular resource is not cached in said cache when said count value is determined to be less than said second threshold value; and, when said count value is determined to be: (i) not less than said second threshold value, and (ii) not greater than said first threshold value, then obtaining said particular resource from another server (104, 106); selectively caching said particular resource in said cache when the amount of free space in said cache exceeds a third threshold; and serving said particular resource obtained in to said client. determining whether a count value associated with said particular resource exceeds a first threshold value, and, based on said determining, when said count value exceeds said first threshold value, obtaining said particular resource from another server (104, 106); caching said particular resource obtained in in said cache regardless of the amount of free space in said cache; and serving said particular resource obtained in to said client; and, obtaining said particular resource from another server (104, 106); caching said particular resource obtained in in said cache regardless of the amount of free space in said cache; and serving said particular resource obtained in to said client; and, based on said determining in, when said count value is determined to be less than a second threshold value, obtaining said particular resource from another server (104, 106); and serving said particular resource obtained in to said client, wherein said particular resource is not cached in said cache when said count value is determined to be less than said second threshold value; and, obtaining said particular resource from another server (104, 106); and serving said particular resource obtained in to said client, wherein said particular resource is not cached in said cache when said count value is determined to be less than said second threshold value; and, when said count value is determined to be: (i) not less than said second threshold value, and (ii) not greater than said first threshold value, then obtaining said particular resource from another server (104, 106); selectively caching said particular resource in said cache when the amount of free space in said cache exceeds a third threshold; and serving said particular resource obtained in to said client. obtaining said particular resource from another server (104, 106); selectively caching said particular resource in said cache when the amount of free space in said cache exceeds a third threshold; and serving said particular resource obtained in to said client.