1. Apparatus, comprising: one or more processors; and computer memory holding computer program instructions that when executed by the one or more computer processors comprise (a) a policy manager, (b) a profile manager, and (c) a privacy-safe targeting engine; the policy manager enabling a policy to be discovered and retrieved by an entity without a specific interaction between a user and the entity, the policy comprising a machine-executed data representation associated with one or more targeting interactions, the policy comprising data logically grouped in one or more URI-addressable fragments, wherein a policy fragment has an associated encoding and protocol-binding to enable the policy fragment to be accessed and applied; the profile manager enabling one or more profiles to be accessed remotely; and the privacy-safe targeting engine using a policy fragment and an audience certification assertion (ACA) to make one or more choices about advertising or content delivery, the audience certification assertion encapsulating into an opaque data token one of: contextual, behavioral and demographic information, wherein the opaque data token certifies that an advertisement or content delivered in response to a request satisfies a targeting criteria associated with the request and that the request has been satisfied in a privacy-safe manner.