Mediation waterfalls: floor changes that invalidate last week’s ROAS
Illustrative worksheet showing how a mediation floor change rewrites historical hybrid ROAS. Floor mechanics cited from Unity LevelPlay mediation management.
Floor experiments silently rewrite historical ROAS if you do not freeze the mediation config version on the cohort. This sheet forces that freeze.
Floor definition
Unity LevelPlay mediation management states you can set a floor price so any bidding network that bids below the floor is excluded from the auction, and that manual rates affect prioritisation rather than reported revenue. Ad-revenue still lands in MMP/mediation reports — see AppsFlyer af_ad_revenue partner sharing.
Synthetic worked example
| Week | Floor (USD) | Realised rewarded eCPM | Hybrid D7 ROAS | Notes |
|---|---|---|---|---|
| W1 | 4.00 | 9.50 | 1.15 | Synthetic |
| W2 (floor raised) | 8.00 | 11.20 | 1.05 | Synthetic — fill rate down |
If UA reads W1 and W2 as one “last week ROAS” without a floor-version dimension, bid changes will chase noise. Freeze mediation_config_id on the cohort export.
| Output | Value |
|---|---|
| eCPM delta W2−W1 | +1.70 |
| ROAS delta | −0.10 |
| Action | Split cohorts by floor version before bidding |
Facts versus limits
| Field | Evidence |
|---|---|
| Floor excludes sub-floor bids | Unity LevelPlay mediation management |
| Observed fill-rate curve | None — synthetic |
