skill-094-pmax-cannibalizing-search-detection

Skill 094: Performance Max Cannibalizing Search Detection

Purpose

Monitor for search query overlap between Performance Max and standard Search campaigns. PMax can cannibalize branded and high-value search traffic, reducing control and potentially increasing costs on proven Search campaigns.

Data Requirements

Data Source: Custom GAQL Required

GAQL Query - Search Terms (Standard Search):

SELECT
  campaign.name,
  campaign.id,
  ad_group.name,
  search_term_view.search_term,
  segments.search_term_match_type,
  metrics.impressions,
  metrics.clicks,
  metrics.cost_micros,
  metrics.conversions,
  metrics.conversions_value
FROM search_term_view
WHERE campaign.advertising_channel_type = 'SEARCH'
  AND segments.date DURING LAST_30_DAYS
  AND metrics.impressions > 10
ORDER BY metrics.impressions DESC
LIMIT 5000

GAQL Query - Campaign Performance Comparison:

SELECT
  campaign.name,
  campaign.advertising_channel_type,
  segments.ad_network_type,
  metrics.impressions,
  metrics.clicks,
  metrics.cost_micros,
  metrics.conversions,
  metrics.search_impression_share,
  metrics.search_exact_match_impression_share
FROM campaign
WHERE campaign.advertising_channel_type IN ('SEARCH', 'PERFORMANCE_MAX')
  AND segments.date DURING LAST_30_DAYS

Run via /google-ads:get-custom with query name pmax_cannibalization.

Standard Data:

• data/performance/campaigns/*/search_terms_metrics_30_days.md - Search term reports

Analysis Steps

1. Compare Campaign Volumes: Track Search impressions on Search vs. PMax campaigns over time
2. Analyze Search Performance Shifts: Monitor impression share changes, brand term performance
3. Identify Overlap Signals: Brand query performance, high-converting keyword trends
4. Assess Impact: Cost efficiency changes, conversion attribution shifts

Thresholds

Condition	Severity
Brand Search impression share drop >10%	Critical
PMax consuming >40% brand queries	Critical
Search campaign CPC increase >20%	Warning
Search conversions drop (brand) >15%	Warning
No brand exclusions in PMax	Info