Metrics question

Google search revenue was down. Figure out why.

Practice this question out loud. An AI interviewer asks it, follows up like a real interviewer would, and scores your answer. Type or speak.

What this question tests

Diagnosing a revenue metric by decomposing it into its real underlying drivers.

Decompose search revenue into query volume, ad-eligible query rate, click-through rate on ads, and cost-per-click, since revenue is a function of all four.
Check for measurement issues first: a reporting pipeline bug, currency conversion issue, or a change in what counts as ad revenue.
Check query volume: did total search queries drop, which would suggest a competitor or platform shift issue, not a monetization problem.
Check ad-eligible rate and CTR: did an algorithm or UI change reduce ad visibility or relevance, hurting clicks even with stable query volume.
Check CPC: did advertiser demand or bidding activity drop, perhaps due to a macroeconomic pullback in ad spend or a policy change.
Segment by geography, device, and query category (commercial vs informational) to isolate where the drop concentrates.

Uses the explicit revenue formula (volume x eligible rate x CTR x CPC) to structure the whole investigation, not a scattershot list.
Separates a demand-side cause (advertiser spend down) from a supply-side cause (fewer or lower-quality queries), since the fix differs completely.
Gives an illustrative finding, e.g. CPC dropped 15% due to a macro ad-spend pullback while volume held steady, marked as an assumption.
Flags a possible internal cause, like an algorithm change reducing ad relevance, as equally plausible as external market factors.

Jumping to 'the economy is bad' without decomposing revenue into its component drivers.
Not distinguishing an external market cause from an internal product or algorithm cause.

Which of the four revenue drivers would you check first and why?
How would you tell if this is a company-specific issue or an industry-wide trend?