1. A method of content delivery in a content delivery network (CDN), the CDN deployed, operated and managed by a content delivery network service provider (CDNSP) and comprising a set of content servers and a domain name system (DNS) associated with a CDN namespace, comprising: establishing a private content delivery network within a portion of the CDN, the private content delivery network associated with a entity distinct from the CDNSP and comprising a subset of the content servers operated by the CDNSP, the private content delivery network further including a private CDN namespace associated therewith that is a subset of the CDN namespace, where the private content delivery network enables the entity to provide content delivery to participating content providers associated with the entity without requiring the entity to deploy, operate and manage content servers; providing the participating content providers associated with the entity on-net content delivery over the private content delivery network; providing the participating content providers associated with the entity off-net content delivery over the CDN on an as-needed basis; wherein the CDNSP manages content server data collection for the private content delivery network; wherein the CDNSP manages billing for the private content delivery network; wherein the CDNSP manages a network operations center (NOC) for the private content delivery network; and wherein the CDNSP manages content storage for the private content delivery network.