Per-ID Bid Modifiers in ADRs

Overview

In Kevel’s auction-based ad delivery system, the bid value (or “price” a buyer is willing to pay for an impression) plays a central role in determining which ad wins a given opportunity. Traditionally, this bid is derived either as a static value based on campaign configuration or through Kevel’s Autobid (target ROAS) system, which optimizes pricing dynamically based on performance.

However, some customers—especially those with programmatic buying platforms, custom optimization models, or real-time pricing data—need greater flexibility and control. These users may already have strong signals about what price they are willing to pay for specific ads, users, or contexts, and want to inject that logic directly into the bidding process without losing the benefits of Kevel’s decisioning framework.

How It Works

Kevel accepts Per-ID Bid Modifiers in Ad Decision Requests (ADRs). These values are provided in the same format as set during campaign management with the addition of additional allowed match types. Specifically, this feature allows customers to submit bid values for specific entities (advertiser, campaign, flight, ad, or creative template field) at request time. These provided values will augment (or optionally override) the default or auto-calculated bids, giving customers full control over how much they’re bidding for a given opportunity.

Integration Notes

• Bid overrides do not need to be provided for all candidate ads in an ADR. For example, when used in tandem with Auction as a Service (passing a list of Product IDs as candidates for the opportunity), the list of products does not need to match the set of bid overrides provided. Any candidate Ads that do not have an override provided will use the price configured in campaign setup.
• Floor prices set on Priorities are still enforced when using this functionality—so, if an override bid is below the floor price the matched ad will be excluded.

Example Ad Decision Request

{
  "placements": [
    {
      "divName": "div0",
      "networkId": 12345,
      "siteId": 667480,
      "adTypes": [
        5
      ],
      "bidModifiers": [
        {
          "match": {"adId": 938034408},
          "multiplier": 2
        },
        {
          "match": {"ctProductId": "450911"},
          "price": 10,
          "forceOverride": true
        }
      ]
    }
  ]
}

Parameters

• bidModifiers — include this array parameter within the desired placement(s). For each modifier include:
  • Match — object containing the entity type and ID to match against
    • options: adId, flightId, campaignId, advertiserId, creative template variable
  • Multiplier / Price — specify the modification as a multiplier on the Flight's Price set in campaign setup or as a fixed value (Price)
  • ForceOverride — if true, ignore any other matching bid modifiers and only use the modifier sent in the ADR (defaults to false). Note: if multiple modifiers sent in an ADR contain force override true and more than one matches, the highest resulting bid will be used.

Reporting

• Bid overrides are included in the pricing object in the ADR response (included if includePricingData is true on the ADR)
• Selection logs include override information

Interaction with Other Overrides and Relevancy Scores

When working with bid overrides, eCPM/eCTR overrides, and relevancy scores, it’s important to understand how these features interact in Kevel’s ad decisioning system. Ultimately, the auction is run against AdRank, which is calculated using eCPM and relevancy.

Bid Modifiers

• If a bid modifier is supplied it is appended to the list of bid modifiers configured via the Campaign Management system (if there are any).
• The bid modifier resulting in the highest bid is used.
• The modified bid is then combined with CTR to generate an eCPM, unless eCPM or eCTR overrides are provided (see below).

eCTR Overrides

• If an override eCTR is supplied, the system uses:
  • The (possibly overridden) bid, and
  • The override eCTR
• These two are multiplied to generate the eCPM used in the auction.
• This allows you to override expected click-through performance while still relying on bids to shape effective value.

eCPM Overrides

• eCPM overrides should not be used with bid overrides.
• eCPM overrides are discouraged and may be deprecated in the future. Instead use a combination of bid overrides and eCTR overrides.

Relevancy Score

• Regardless of whether bid, eCPM, or eCTR overrides are applied, the resulting eCPM is always combined with the ad’s relevancy score to influence the final AdRank.