A sub-publisher is a sub-advertiser where mobile ads actually run. A sub-publisher collects campaign data from publishers who directly get in touch with advertisers. Publishers work with a lot of sub-publishers to run their mobile ad campaigns but advertisers don’t communicate with them directly.

Publishers don’t have their own inventory to run mobile advertising campaigns. Instead they are either automatically or manually integrated with sub-publishers. 

Sub-publisher management includes campaign optimization, mobile ad fraud detection, targeting options. Most ad networks mask their sub-publisher lists and don’t want to share this information with advertisers. Instead they share an internal code to let advertisers see sub-publisher based data. Whitelisting and blacklisting is done through those codes instead of the real names of su-publishers.