Spreadsheet Rule vs. GA4 Model: A Churn-Scoring Head-to-Head
Objective: Given the same 20-customer behavior export, score churn risk two ways, a simple rule-based spreadsheet model and GA4's built-in churn probability logic, and decide which one a lean team should operate now.
Coinbase's retention team won't get a data-science hire for two quarters. You have to decide whether a rule-based spreadsheet score is good enough to run retention campaigns on until GA4's predictive audiences fully activate.
Score both models against the same customers, compare both to actual outcomes, and make the call on which one ships this week.
Before you start
What you'll need
Free path (everything below is enough to finish)
Free, and the scoring logic stays visible and auditable to a non-technical retention team
No cost, no setup beyond an active GA4 property with sufficient conversion volume
The process
2 steps
Step 01 of 02
The lesson's Step 3 describes a rule-based propensity model: take past churned customers, write down what they had in common (days since last purchase, low email opens, no logins), and build a simple scoring rule from those signals.
Past churned Coinbase users share 3 traits: no login in 45+ days, 2+ failed payment attempts, and a support ticket in the last 30 days. How do you turn that into a score for the current 20-customer list?
Procedure
- Import customer-behavior-export.csv
- Add 1 point per matched trait: no login 45+ days, 2+ failed payments, recent support ticket
- Sum points per customer into a rule_score column (0-3)
- Flag anyone with rule_score >= 2 as high risk
customer_id no_login_45d failed_pay support_ticket rule_score flag C-1042 1 1 0 2 HIGH C-1058 0 0 1 1 low C-1071 1 1 1 3 HIGH
Healthy
The rule-based score correctly separates most of the 20 customers into sensible risk tiers using only data already sitting in the CRM, no model training required.
Unhealthy
The rule flags almost everyone or almost no one as high risk, meaning the point thresholds need recalibrating against real churned-customer traits, not guessed.
What this means
A rule-based score is a legitimate propensity model, it's just hand-built instead of machine-learned, and it works when the underlying traits are genuinely predictive.
So what do I do about it?
| Symptom | Action | Effort |
|---|---|---|
| The rule-based flag matches almost no one to 'high risk' | Re-derive the point thresholds from a fresh sample of the last 50 actually-churned customers | 30 min |
Step 02 of 02
The lesson notes GA4 activates free predictive metrics, including churn probability, automatically once a property has at least 1,000 returning users who triggered the conversion event in the past 28 days.
GA4's churn-probability export for the same 20 customers flags 7 as high risk. The rule-based score flags 9. Comparing both to actual 30-day outcomes, which one should the team operate on this week?
Procedure
- Add GA4's churn-probability flag as a new column
- Add the actual 30-day outcome column
- Calculate how many true positives each method produces
- Compare against the effort each method requires to maintain
Method Flagged True Positives Setup Effort Rule-based score 9 6 Built today, in Sheets GA4 churn model 7 6 Already running, free, updates automatically
Healthy
Both methods catch a similar number of true churners, so the team picks GA4's version since it updates automatically with zero manual maintenance.
Unhealthy
The team keeps maintaining the rule-based spreadsheet manually every week even though GA4's free model performs equally well with no upkeep.
What this means
When two methods perform comparably, the tiebreaker is which one keeps working without someone manually re-running it every week.
So what do I do about it?
| Symptom | Action | Effort |
|---|---|---|
| Both methods catch a similar share of real churners | Retire the manual rule-based sheet and route retention triggers off GA4's predictive audience instead | 30 min |
Final deliverable
A head-to-head scorecard comparing the rule-based score and GA4's churn probability against actual outcomes, with a recommendation on which to operate this quarter.
See a reference example
Chewy, Churn-Scoring Head-to-Head (excerpt) Rule-based score: 8 flagged, 6 true positives, manual weekly upkeep GA4 churn model: 6 flagged, 6 true positives, automatic RECOMMENDATION: Adopt GA4's model. Equal accuracy, zero manual maintenance.
Success criteria
You're done when you can:
- Builds a working rule-based score from named customer traits
- Correctly compares both methods' true-positive counts against actual outcomes
- Recommendation weighs maintenance effort, not just raw accuracy