Ends the trial/pricing A/B/C experiment. Everyone gets the control offer
— a free trial — and the trial length becomes a per-plan setting.
## Trial length
| Plan | Before | Now | Env override |
|---|---|---|---|
| Yearly | 15 days | **15 days** | `STRIPE_PRO_YEARLY_TRIAL_DAYS` |
| Monthly | 15 days | **7 days** | `STRIPE_PRO_MONTHLY_TRIAL_DAYS` |
**Note that monthly 15 → 7 is a new bet, not a rollback.** The control
arm was 15 days on both plans, and 7 days on monthly is a value the
experiment never tested (`reduced_trial` was monthly 3 / yearly 7). The
rationale is that the longer commitment earns the longer trial; it ships
here at the same time as the instrument that could measure it is
removed, so it will not be measurable as an isolated effect.
## Final experiment numbers
Archived here because `stats:experiment-funnel` and its collector are
deleted by this PR and the purge migration's `down()` is a no-op.
| Variant | Assigned | Subscribed | Active | Refunded |
|---|---|---|---|---|
| control | 597 | 46 | 13 | 0 |
| reduced_trial | 590 | 50 | 10 | 0 |
| pay_now | 609 | 41 | 21 | 18 |
| legacy | 94 | 55 | 31 | 0 |
## What is deleted
- `App\Features\SubscriptionExperiment` (the Pennant A/B/C assignment)
and the `ExperimentOffer` service.
- The `pay_now` self-service refund: `RefundSelfServe`, the
`settings.billing.refund` route, the controller actions and Discord
embeds, the money-back card in billing settings, and the
`stripe:verify-refund` sandbox command.
- The weekly `stats:experiment-funnel` report, its collector, and the
`ProportionSignificance` / `BinomialProportion` helpers it was the only
caller of, plus its schedule entry.
- The `subscriptions.experiment.*` config block and the orphaned
`es`/`fr` translation strings.
- A data migration purges the ~1,890 stored Pennant assignments.
`subscriptions.refunded_at` is deliberately **kept**: nothing reads it
anymore, but it is the only record of the 18 refunds the experiment
issued. The migration carries a comment saying so.
## Fixes found in review
- **The surviving funnel report was mis-scoring conversions.**
`SubscriptionFunnelCollector` compared every cancellation to one global
trial length. With trials now diverging per plan, a monthly subscriber
who was billed and cancelled on day 10 was scored as never having paid.
It now reads each subscription's own `trial_ends_at`, and the longest
plan trial is used only for deciding when a cohort is old enough to
score. Covered by two new tests.
- **The trial length swapped silently.** It lived on a single line under
the plan selector, which rewrote itself when the user switched plan. Now
that the plans genuinely differ, each plan card shows its own length.
- The report legend no longer quotes a single trial length for both
plans, and warns that the experiment weeks are still inside its window.
## Before merging
- [x] **Unset `SUBSCRIPTION_EXPERIMENT_STARTED_AT` in production** so no
new `pay_now` assignment happens while this waits. Anyone who checks out
under `pay_now` between now and the deploy is charged upfront and then
loses the one-tap refund they were promised at the point of payment.
Checked just before opening this PR: **0 `pay_now` subscriptions
currently inside the 3-day window**, so nobody is stranded today.
- [x] Drop the now-orphaned `SUBSCRIPTION_EXPERIMENT_*` variables from
the production env with the deploy.
- [x] If old containers are still serving while the purge migration
runs, a few assignments can be re-resolved and reappear. Harmless —
re-run `php artisan pennant:purge "App\Features\SubscriptionExperiment"`
once the deploy settles if you want the table clean.
Support note: a manual Stripe refund for a former `pay_now` user will
not disconnect their bank connections, which the automated flow used to
do.
## Demo
https://github.com/user-attachments/assets/3614d488-05c6-405d-a687-bbf45746879a
<!-- PLACEHOLDER: drag the QA video here -->
## QA
Browser-tested against the running app:
- Paywall: annual card shows "15 days free", monthly card "7 days free";
the terms line under the selector follows the selected plan (15 ↔ 7);
mobile viewport renders fine.
- Billing settings: no money-back card for a free user or an active
subscriber; `POST /settings/billing/refund` returns 404.
- No console or network errors on any screen.
- `stats:subscription-funnel` still renders and posts.
- The purge migration leaves 0 `SubscriptionExperiment` rows.
Full suite green (2045 tests) apart from the known local-only
`DashboardTest` 409; `pint`, `lint`, `format` and `build` all clean.
## Summary
Audited `stats:experiment-funnel` end-to-end (data acquisition, queries,
per-row counting, financial math, and statistics) and fixed the issues
that made it misleading for the win/no-win decision. The report used to
rank variants by an **absolute** contribution-margin total that
mechanically favoured whichever variant matured fastest, and it declared
statistical significance with a normal approximation that is invalid at
the small conversion counts this experiment has.
## What changed
**Presentation & comparability**
- Replace `A2P%` (numerator not a subset of the denominator → could
exceed 100%) with `Conv%` = conversions ÷ matured-assigned — always
≤100% and comparable across variants.
- Print `MatU` (matured cohort size) so the rate denominators are
visible and the table reconciles; revive `ARPU`.
- Reframe the guidance: compare on per-user `Conv%`/`ARPU`, not the
absolute `MRR`/`Cost`/`Burn`/`CM` totals (which scale with `MatU`).
**Data correctness**
- Count soft-deleted users (`withTrashed`) — they were assigned a
variant and their connections incurred real cost.
- Attribute by the deterministic `SubscriptionExperiment::bucket()`
instead of the resolved Pennant flag, so setting `force_variant` (the
winner rollout switch) no longer collapses the whole report onto one
variant. Also stops writing Pennant rows as a side effect.
- Resolve `MRR` for subscriptions on rotated/archived Stripe price ids
(fetch prices by product), warn on any net-active sub whose price is
unmapped, round yearly ÷ 12, and skip foreign-currency prices.
- `Burn` counts only users who never earned net revenue (no
subscription, or paid-then-refunded) — a paid-then-churned user is no
longer booked as connect-and-leave leak.
**Statistics**
- Measure conversion as "ever charged, net of refund" (time-invariant)
instead of a live active-now snapshot that biases older cohorts (which
have had longer to churn).
- Decide significance with **Fisher's exact test** (exact at any sample
size), Bonferroni-corrected over the three arms, instead of the
normal-approx z that overstates evidence when expected cell counts fall
below 5. Add a Newcombe difference-of-proportions CI and a small-sample
caveat.
- Extract the inference into `App\Services\Stats\ProportionSignificance`
(+ a `BinomialProportion` value object), with unit tests that pin the
exact interval and p-value numbers.
## Validation
Reconstructed every column in raw SQL against a production dump — all
reconcile **to the cent / to the row**. Independent recomputation of the
statistics (Wilson, Fisher exact, Newcombe, z) matches the command's
output.
## Testing
26 tests (20 feature + 6 unit, 94 assertions). `pint` and
`phpstan`/larastan green.
## Note
This branch also carries two small pre-existing commits unrelated to the
funnel (`fix(categories): fall back to gray…`, `chore(schedule): stop
scheduling the stuck cohort report`). Happy to split them into their own
PR if preferred.
Víctor Falcón