A computer implemented method and system for managing audience data for advertisement placements is disclosed. A server receives a source signal stream comprising metadata and an advertisement space. The server extracts from the metadata a channel identifier, a private client identifier, and information about an intended audience of interest to advertisers. The server identifies a placement opportunity including an owner of the advertisement space based on the channel identifier. The server purges at least some of the extracted information about the intended audience when the owner of the advertisement space is identified as a national network. The server identifies an amount of information about the intended audience to purge and subsequently to fetch for the national network based on a business arrangement between the national network and a service provider, which the server enforces and enables.