The short version

Auction insights shows which other advertisers competed in the same auctions you did, and how you compared. It is the only report that tells you whether a change in your performance came from inside your account or from the market around it.

When CPM or CPC rises and nothing in your account changed, this is where you find out why.

What it shows

  • Impression share — each competitor's share of the auctions you both entered.
  • Overlap rate — how often a competitor appeared when you did.
  • Position or rank comparison — how often they appeared above you.
  • Outranking share — how often you ranked higher than them.

What it does not show is spend, budget, or performance. You learn who is present and how you compare, not what it is costing them.

The three questions it answers

1. Did a new competitor arrive?

A name that was not there last month with meaningful overlap explains a cost increase you could not otherwise account for. This is the most common use, and it converts an unexplained CPM rise into a known cause.

2. Is an existing competitor pushing harder?

Rising overlap and rising outranking from a familiar name means someone increased budget or bids. Your performance decline is their spending increase.

3. Am I competing where I think I am?

Unexpected names indicate your targeting reaches auctions you did not intend. In search, that usually means match types are pulling in queries outside your intended set.

Reading it without over-reading it

A few cautions worth holding.

  • Overlap is not competition for the same customer. A broad advertiser can overlap heavily while chasing different intent.
  • Being outranked is not automatically bad. Top position costs more and does not always convert better. Deliberately ranking lower on expensive terms is a legitimate strategy.
  • It is directional, not precise. Treat it as evidence about market movement, not as a measurement.

What to do with it

A new competitor with high overlap. Decide whether to compete on price or differentiate. Matching their bids on their strongest terms is usually the expensive option.

Rising outranking against you across the board. Check quality and relevance before bids — rank is not only price.

Unexpected advertisers appearing. Audit your match types and search terms. You may be paying to compete in auctions you never meant to enter.

Practical rule

Check auction insights before concluding a performance change came from your account. If a competitor's overlap and outranking rose in the same period, the market moved and your account did not — and the response to those two situations is entirely different.

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