Redirect-based split tests lose a median 50-200ms and that latency alone can fake a −1 to −3% loss.
The mistake: blaming the variant's design when the extra hop, not the layout, suppressed conversion.
— The control loads native; the variant eats a redirect penalty users feel.
— Fix: serve both variants server-side or via the same edge, equalize load time, and verify by checking time-to-interactive parity before reading CVR.
Read the number, not the story. [redirect tax 50-200ms]

Running 4 overlapping tests on the same checkout assumes additivity — and interactions can erase 30% of stacked gains.
The error: summing four individual +3% wins to forecast +12%. Effects aren't independent when they touch the same flow.
— Two friction-reducers can't each "remove the same friction."
— Fix: use mutually exclusive traffic buckets for conflicting tests, or a factorial design that estimates the interaction term directly.
Read the number, not the story. [Σ wins ≠ combined · interaction]

ЕЮ Иванов продолжает кошмарить АффПапу, конторку, которая накинула говна на вентилятор этим летом. Тогда в AffPapa не знали, с каким говном идут бодаться, поэтому заслуженно проиграли. 😏

На этот раз ЕЮ зарегал товарный знак AffPapa — совсем скоро имя компании будет официально принадлежать ему. Чтобы убедиться в трушности мува, переходим по ссыл-Очке и вводим серийный номер: 2026793242. Там видим, что заявка на регистрацию подана лично Евгением Юрьичем.

Всё это выглядит забавно, но давайте не забывать, в какой сфере мы работаем и что реально может произойти с жирным троллем за воровство нейминга. Впрочем, толстому не привыкать отхватывать пиздов за проделки в интернете, поэтому ждем очередную фотку разбитого ебала и длинный пост с извинениями. 😏😏😏

В арбитраже денег нет 💵

"+5% lift" with a 95% CI of [−2%, +12%] is a coin flip dressed as a win.
The mistake: reporting the point estimate and hiding the interval. A CI straddling zero means you cannot rule out a loss.
— Decks show the 5%; the bracket that contains zero gets cropped.
— Fix: lead with the interval, not the point. Decide on the lower bound: would you still ship if true lift were −2%?
Read the number, not the story. [+5% · CI [−2%, +12%]]

A 3-day test misses the weekly cycle and can be off by ±2-4 points on weekday-skewed traffic.
The failure: stopping mid-week, when B2B checkout converts higher Tue-Thu. You measured a day-of-week, not a variant.
— Payday cycles and weekends shift intent too.
— Fix: run in whole-week multiples so each variant sees identical day composition. Minimum one full cycle, never partial weeks.
Read the number, not the story. [≥1 full week · ±2-4pp]

Iterating button colors gets you 0.x% wins while the real 15% sits in a structural change you never test.
The mistake: optimizing toward a local maximum — endless micro-tweaks on a checkout that should be re-architected (guest checkout, fewer steps).
— Small safe tests crowd out the big risky one.
— Fix: budget ~20% of test slots for bold structural variants. Measure the ceiling (best-case flow) so you know the gap you're leaving.
Read the number, not the story. [micro 0.x% vs structural ~15%]

Iterating button colors gets you 0.x% wins while the real 15% sits in a structural change you never test.
The mistake: optimizing toward a local maximum — endless micro-tweaks on a checkout that should be re-architected (guest checkout, fewer steps).
— Small safe tests crowd out the big risky one.
— Fix: budget ~20% of test slots for bold structural variants. Measure the ceiling (best-case flow) so you know the gap you're leaving.
Read the number, not the story. [micro 0.x% vs structural ~15%]

Five user-test quotes feel like proof but carry a margin of error near ±40 points.
The mistake: treating moderated session feedback as quantitative evidence and shipping on vibes. n=5 estimates a rate within roughly ±0.4 at best.
— Useful for finding hypotheses, useless for sizing them.
— Fix: use qualitative to generate the test, A/B to decide it. Never let a strong quote override a non-significant number.
Read the number, not the story. [n=5 · MoE ≈ ±40pp]