Patent ID: 8255489

Claim:
Apparatus for use in a content delivery network (CDN) in which participating content providers offload given content for delivery from content servers managed by a content delivery network service provider, comprising: a processor; a computer memory holding computer program instructions that when executed by the processor perform a method comprising: tracking a client machine user agent across a plurality of content provider domains being managed by the content delivery network service provider, wherein the client machine user agent is an atomically identifiable web client, the tracking including the following sub-steps carried out with respect to at least one content provider domain visited by the client machine user agent: redirecting the client machine user agent from the content provider domain to a content delivery network service provider namespace and setting a master cookie, automatically redirecting the client machine user agent back to the content provider domain from which the client machine user agent was redirected; and setting a content provider domain-specific cookie equal to the value of the master cookie; and with permission of a first participating content provider, providing a second participating content provider with information obtained during the tracking step, wherein the information tracks the client machine user agent across one or more content domains associated with the first participating content provider and includes an indication that the client machine user agent has visited the one or more content domains.