Every Campaign, Line Item, and Creatives belongs to an Advertiser. Advertisers are typically the entity paying the bills for the ads that run. See: Advertisers, Campaigns, Line_Items, Creatives.
|POST||Advertiser name must be unqiue|
|PUT||Cannot make the Advertiser inactive if there are active Campaigns that it owns|
|DELETE||Cannot delete the Advertiser if there are any Campaigns that it owns|