Methods, systems, and apparatus, including computer programs encoded on a computer storage medium for managing a relationship between content and an environment for provisioning the content. In one aspect, a method includes receiving a request for a content item; and in response to receiving the request: selecting a creative from a plurality of creatives, the creative including a reference to a profile associated with one or more elements; retrieving content data from one or more content feeds bound to the elements; and delivering the creative and the content data to a user device.