Methods, apparatuses, and systems are provided for improving utilization of the communications system through various “deltacasting” techniques for handling content sets (e.g., feeds or websites). In some embodiments, within a client-server context, content sets are anticipatorily pre-positioned in client dictionaries using multicasting techniques to share forward link capacity. Pre-positioning determinations are made according to byte-level data, set-level metadata, and/or user preferences. In some embodiments, when locally stored information from the content sets is requested by a user, deltacasting techniques are used to generate fingerprints for use in identifying and exploiting multicasting and/or other opportunities for increased utilization of links of the communications system.