Table of Contents
Why rebills change the real winner of a test
The early winner illusion
Most tests declare a winner based on early results.
Higher conversion rate. Better EPC. Stronger initial revenue.
A winner is chosen. Traffic is shifted. Scale begins.
Then rebills arrive.
CBSplit was built to show why early winners often lose later.
Front-end tests ignore subscription survival
Many offers include subscriptions.
Tests usually measure:
* Initial purchase conversion * Average order value * Cost per acquisition * Early profitability
They rarely measure:
* First rebill success * Second rebill retention * Long-term churn * Refund timing
Rebills redefine what “winning” means.
Two variants can win differently over time
Variant A may win on day one by:
* Converting more users * Driving higher front-end revenue
Variant B may:
* Convert fewer users * Generate slightly lower initial revenue * Produce stronger subscription retention
Early dashboards crown Variant A.
Rebills often crown Variant B.
CBSplit waits for time to reveal the truth.
Rebills expose alignment, not persuasion
Front-end wins often reflect persuasion strength.
Rebills reflect alignment strength.
Alignment means:
* Expectations match delivery * Customers understand billing terms * Value continues beyond impulse
Persuasion can win the click.
Alignment wins the rebill.
CBSplit measures both.
Rebills amplify small quality differences
Minor differences in:
* Messaging clarity * Offer framing * Upsell positioning * Billing transparency
Can produce large differences in:
* Churn rate * Refund rate * Subscription longevity
These effects compound over time.
CBSplit tracks compounding behavior, not just initial events.
Early testing windows hide delayed revenue
Short testing windows favor:
* Quick approvals * Aggressive tactics * High-pressure offers
Longer observation windows reveal:
* Sustained revenue * Stable cohorts * Durable customer behavior
CBSplit extends the evaluation horizon beyond the test window.
Rebills alter lifetime value calculations
When rebills are included:
* LTV shifts * ROAS changes * Scaling thresholds move * Risk exposure becomes visible
A variant that looks profitable early can become unprofitable after churn is accounted for.
CBSplit recalculates performance after rebill cycles complete.
Why most tests stop too early
Tests stop early because:
* Teams want fast decisions * Traffic costs money * Dashboards emphasize immediacy * Patience feels expensive
But premature decisions often cost more in the long run.
CBSplit encourages outcome-based evaluation, not event-based victories.