Table of Contents
Why classic A/B testing lies in subscription funnels
The experiment illusion
Classic A/B testing assumes clarity.
Two variants. One metric. A winner.
In subscription funnels, this model breaks.
CBSplit was built because subscription revenue does not behave like single-purchase revenue.
Classic A/B testing measures the wrong moment
Most A/B tests declare winners based on:
* Initial conversion rate * Front-end revenue * EPC * Cost per acquisition
Subscription funnels generate revenue over time.
The true outcome depends on:
* First rebill success * Second rebill retention * Refund timing * Churn velocity
Classic A/B testing stops before these signals mature.
Early winners often lose later
Variant A may:
* Convert more aggressively * Generate higher front-end revenue * Show stronger short-term metrics
Variant B may:
* Convert slightly less * Produce stronger retention * Deliver higher lifetime value
Classic A/B testing crowns Variant A.
Rebills often crown Variant B.
CBSplit waits for lifecycle truth.
Subscription funnels amplify small differences
Minor differences in:
* Messaging tone * Billing clarity * Upsell sequencing * Expectation framing
Can create large differences in:
* Refund rates * Churn timing * Rebill survival
Classic A/B testing rarely runs long enough to capture compounding effects.
CBSplit tracks cohort durability.
Statistical significance ignores lifecycle complexity
Traditional A/B tests aim for statistical significance.
They assume:
* Stable conditions * Immediate outcomes * Linear conversion paths
Subscription funnels are:
* Non-linear * Delayed * Affected by retries and rebills * Influenced by fulfillment quality
Significance at checkout does not equal significance over time.
CBSplit evaluates outcome stability, not just event frequency.
Short test windows create structural bias
Short testing windows favor:
* High-pressure copy * Urgency-driven conversions * Impulse behavior * Aggressive billing framing
These tactics often increase early revenue but weaken retention.
Classic A/B testing rewards speed.
CBSplit rewards durability.
Refund and churn distort true performance
Refunds and churn:
* Reduce net revenue * Shift LTV curves * Alter ROI thresholds * Impact processor health
If these are excluded from evaluation, test results are incomplete.
CBSplit integrates refund-adjusted and rebill-adjusted outcomes.
Subscription truth is delayed by design
Subscription revenue unfolds over cycles.
Real performance becomes visible only after:
* Multiple billing attempts * Cohort aging * Refund windows closing
Classic A/B testing assumes truth is immediate.
CBSplit assumes truth is delayed.