The Bid Modifier and Delivery Modifier APIs have been upgraded and all customers should use the new 2.0 APIs described here.
Bid Modifiers and Delivery Modifiers (together "Modifiers") are objects allows bids to be modified in real time based on various criteria.
A Bid Modifier adjusts the amount to bid on a given auction. A Delivery Modifier adjusts the relative weight of the Line Item's budget to allocate to a given auction.
A single Modifier object can be associated with multiple Line Items or Campaigns. Campaign-level Modifiers apply to any Line Items owned by the Campaign that do not themselves have Modifiers associated.
Bid Modifier can have either a list of "Terms" that determine how the bids are modified or a Bid Models associated, or both. Delivery Modifiers must have either Terms or a Model, but not both.
Terms follow the same pattern of
module->key as are used in Targeting and can be referenced in this Google Sheet. A complete description of how Bid Modifier Terms may be used is here: Bid Modifier Terms.
Note: Both Bid Modifiers and Delivery Modifiers must be enabled for your Buzz instance.
Cannot delete Bid or Delivery Modifiers if there are any Line Items or Campaigns associated.