What is Tracking Mismatch?

Tracking Mismatch is the gap between the conversions Google Ads reports and the conversions GA4 can verify — the raw count difference that Smart Bidding silently treats as real.

Why it matters

Google Ads counts view-through, cross-device modeled, and attribution-predicted conversions alongside real click-through conversions. The algorithm bids on all of them. When your own analytics cannot confirm a large share, the bidding model is being trained on data nobody can verify.

How ClickCatalyst detects it

The absolute gap is Google Ads conversions minus GA4 conversions over rolling 30-day totals. Comparing the 7-day gap against the 30-day gap separates recent breakage ("something changed this week") from structural drift (different measurement windows).

Signal density checks whether the algorithm even has enough data to learn: fewer than 1 conversion per 100 clicks over 7 days means Smart Bidding is flying blind. Signal volatility measures whether the gap is stable (manageable) or swinging daily (worse — the model can never settle).

Each campaign then receives a Bidding Trust verdict — Safe, Caution, or Do Not Trust — based on tracking reliability, conversion volume, and platform agreement. A "Do Not Trust" campaign should run manual bidding until tracking is repaired.

absolute_gap = ads_conversions − ga4_conversions   // 30d rolling

signal_density = conversions per 100 clicks (7d)
drift windows:  drift_7d_pct vs drift_30d_pct

Example

One audited campaign reported 59 conversions in Google Ads while GA4 recorded zero — a 27% account-level attribution drift feeding Smart Bidding pure phantom signal.