Aspects of the subject technology receiving, by a campaign client module and via an advertisement network server, a hierarchical campaign identifier including one or more sub-identifiers. The campaign client module also accesses, from an aggregation server, anonymity data. The campaign client module also selects a sub-identifier from the one or more sub-identifiers of the hierarchical campaign identifier based on the anonymity data, generates a reporting data structure including a set of data based on the sub-identifier, and transmits the reporting data structure to the advertisement network server.