Per-ID eCTR + eCPM Overrides

Overview

Kevel’s ad server is designed to balance automation with control. While Kevel predicts ad performance using historical click-through and conversion data, we understand that retailers often have deeper, real-time context that isn’t visible to the Kevel decision engine.

The Per-ID eCTR and eCPM Overrides feature allows you to bring your own understanding of expected ad performance—whether from internal machine learning models, business logic, or domain expertise—into Kevel’s auction engine. By doing so, you gain the benefits of Kevel’s targeting, pacing, and reporting systems while fine-tuning performance based on data only you have.

How It Works

Override predicted eCTR (expected click-through rate) or eCPM (effective cost per mille) values per request by including an eCtrOverride or eCpmOverride parameter in the placements block of in your Ad Decision Request (ADR). These values can be scoped to specific IDs, such as advertiser, campaign, flight, ad, or creative template fields.

This mechanism supports:

• Granular overrides — specify expected performance at any level of the ad hierarchy
• Burn-in control — optionally apply overrides only until an ad accrues sufficient data, or persist them beyond
• Flexible use cases — plug in performance predictions from your own models or tools

Example Use Cases

• A retailer uses internal ML models to estimate click likelihood for each product ad based on merchandising data and customer behavior
• An advertiser wants to launch a campaign with known promotional performance expectations
• A platform integrates a custom bidding or ranking layer while still leveraging Kevel’s full delivery infrastructure

Integration Notes

• If both eCTR and eCPM overrides are provided, Kevel will prioritize the eCPM value
• When multiple ID attributes match, the highest override value is used
• If no overrides match, Kevel falls back to its default performance estimation
• Overrides respect the eCPM optimization settings configured on the Flight:
  • Floor eCPM: override will not be below this eCPM.
  • Ceiling eCPM: override will not be above this eCPM.
  • Multiplier: override will be multiplied by this factor.

Example Ad Decision Request

{
  "placements": [
    {
      "networkId": 123,
      "siteId": 456,
      "adTypes": [5],
      "eCtrOverride": {
        "forceOverride": false,
        "idAttribute": {
          "adId": {
            "9945867": 0.025,
            "8893776": 0.03
          },
          "ctFoo": {
            "bar": 0.015,
            "baz": 0.05
          }
        }
      }
    }
  ]
}

Parameters

• eCtrOverride — Override the click through rate of specific ads by ID attribute.
• eCpmOverride — Override the eCPM of specific ads by ID attribute.
• ID attribute options: adId, flightId, campaignId, advertiserId, creative template variable
• forceOverride — if true, the override is applied throughout the lifetime of the Ad. Otherwise, the override is only applied to the default eCPM during the burn-in period, and the final eCPM is the linear interpolation between the override eCPM and the true eCPM derived from past performance.