Every experiment,
whichever way
it landed.
Failures are published at the same size as wins — that is the whole point.
1Win
1Inconclusive
1Negative
Win · medium confidence
Ask people to invite a colleague right after their first exportAna Ribeiro · A solo founder · €390Challenge window closed 19 Jul 2026Measured by: share of sign-ups that came from a referral
4% before, changing to 11%Manually verified · 6 JulInconclusive · low confidenceA launch-day post keeps sign-ups high for a monthAna Ribeiro · A solo founder · €150Challenge window closed 12 Jun 2026Measured by: sign-ups per week
40/wk before, changing to 43/wkManually verified · 30 MayNegative · high confidenceSearch ads on the words people type when ready to buyRui Santos · A solo founder · €500Challenge window closed 27 Apr 2026Measured by: what one sign-up cost, against the target
€9 before, changing to €31Manually verified · 14 AprThese experiments were paid for by the founders themselves. No pledge has been recorded here yet, so nothing on this page was funded by a backer — the mechanism is real and the money has not run through it. They also all come from one founder, and most of the ideas from one person, so treat what is here as a handful of readings from a single product rather than evidence about what works generally.