1. A method comprising: receiving a first copy of a content dataset at a server optimizer of a communications network without a corresponding request for the content dataset from a first client terminal over the communications network; calculating an anticipatory dataset as a function of the content dataset, such that the anticipatory dataset represents at least a substantial portion of the content dataset but cannot be used to reconstruct the content dataset without a keying dataset that is also calculated from the content dataset; communicating the anticipatory dataset to the first client terminal from the server optimizer over the communications network for anticipatory storage of the anticipatory dataset local to the first client terminal; and subsequent to communicating the anticipatory dataset to the first client terminal: intercepting a second copy of the content dataset at the server optimizer, the second copy of the content dataset being communicated to the first client terminal in response to a content request issued by the first client terminal for the content dataset; calculating the keying dataset as a function of the second copy of the content dataset at the server optimizer; and communicating the keying dataset from the server optimizer to the client terminal for use by the first client terminal in locally reconstructing the content dataset as a function of the keying dataset and the anticipatory dataset.