GTM, consent, GA4
Measurement
Whether Consent Mode v2 collects signals, or cuts tracking off in the EU.
Whether enhanced conversions pass SHA-256 to Google Ads.
Trigger loops, duplicate purchase and lead events, and errors in the dataLayer.
Whether orders land on PayU, Przelewy24, or the bank instead of on the campaign.
Cannibalization
Architecture
Search against Performance Max and the product campaigns.
Whether broad match pulls in informational traffic.
Whether the group, the responsive ad, and the landing page say the same thing.
30, 60, and 90 days
Queries and placements
Queries that spend and have not a single conversion.
Whether jobs, logins, reviews, guides, and free samples were excluded.
Display and YouTube: children's apps, games, and sites built to catch the ad.
Lost impressions
Bids and budget
Lost impression share from budget and from rank.
Whether Target ROAS and Target CPA are too cautious, or unrealistic for the funnel.
Where a higher budget raises profit in a straight line, and where it eats the margin.