Paid Ads

Auction Overlap

Auction overlap measures how often your ads compete in the same auctions as another advertiser. It can explain CPM/CPC pressure and ranking dynamics.

Updated 2026-01-24

Definition

Auction overlap measures how often your ads compete in the same auctions as another advertiser. It can explain CPM/CPC pressure and ranking dynamics.

How to use it

  • Use overlap and outranking share to understand competitive pressure.
  • Do not chase impression share blindly; use marginal ROAS and profit constraints.

Why this matters

This term matters because it affects how you interpret performance and make budget decisions. If you use inconsistent definitions or windows, ROAS/CPA can look "better" while profit gets worse.

Practical checklist

  • Write a 1-line definition for "Auction Overlap" that your team will use consistently.
  • Keep the time window consistent (weekly/monthly/quarterly) when comparing trends.
  • Segment results (channel/plan/cohort) before drawing big conclusions from blended averages.
  • Sanity-check with a related calculator from the same category on MetricKit.
  • Read the related guide (e.g., Marginal ROAS: how to scale ads with diminishing returns) for context and common pitfalls.

Where to use this on MetricKit

Calculators

Guides