CTR impact
also called Expectation-gap impactWeighted CTR gap
Definition
How material a row's expectation gap is, expressed in clicks: the size of the gap multiplied by the impressions it applies to.
How it's calculated
impact = |actualCtr − expectedCtr| × impressions, rounded to two decimals. It is the ranking key for both the over-performer and the under-performer lists.
Scope, grain and dimensions
- Grain
- One keyword × one page × the window.
- Dimensions
- query · page · brand · intent · device
- Required filters
- date range
- Aggregation
- Row-level, and deliberately unsigned, direction lives in the CTR delta, magnitude lives here.
- Metric type
- derived metric · clicks over the window (modeled)
Data sources
Where you'll see this
Named reports that normally include this metric.
Skills and analyses that use it
Skills carry the judgment; the analysis verbs do the reading.
Skills
Analysis verbs
ctr_curve_model
Method rungs and levers
A rung tells you what a movement here can and cannot explain, read the rungs below it first.
levers L3 Refresh & content quality
Ask Quattr
- "Which CTR gaps are actually worth fixing?" Simulate this →
- "Rank our snippet opportunities by clicks at stake" Simulate this →
How to read it
The reason the worklist is ordered the way it is: a large gap on a rarely-seen query is worth less than a small gap on a heavily-seen one. It sizes materiality, and it should never be read as clicks that were lost, the expectation is modeled, not observed.
Caveats, freshness and failure modes
Absolute value: a large impact figure can belong to an over-performer, so it is only interpretable beside the sign of the gap.
Modeled against a fitted expectation, so it inherits every caveat on that curve, including its non-stationarity.
Holds impressions constant at their observed level, a rewrite that changes ranking changes the impressions too.
- Freshness
- 1 to 2 days behind, Google's own reporting lag. Any answer touching the last 48 hours says so on the card.
Common failure modes
- Reporting the impact figure as clicks lost to a bad title.
- Summing impact across a worklist and presenting the total as a recoverable number.
Related metrics and workflows
Verification
A definition is the smallest part of this.
The measurement matters because something acts on it. Here is the rest of the showcase, in the order most people find useful.