Satispay
Satispay was built for person-to-person payments — reimbursing dinner, splitting rent, paying the babysitter. In the very first months, however, the team observed something unplanned: users who already had Satispay started spontaneously asking each other whether they could pay the shops they visited.
This signal — organic demand towards merchants, not towards other private users — was the real product-market fit. Not the one imagined in the business plan, but the one emerging from behaviour.
Satispay responded by aggressively recruiting merchants in the neighbourhoods where private user penetration was already high. Not market by market geographically, but block by block: when an area of Milan already had enough users, the team physically visited local merchants to eliminate switching friction.
The clearest PMF signal: the retention rate of users who had used Satispay at least once to pay a merchant was three times higher than those who had only used it for person-to-person payments. Commercial use created daily habit; person-to-person payment was occasional.
Today Satispay has over 4 million active users. The real product-market fit was in daily merchant payments, not in the original idea.
Product-market fit is often not where you look for it — it is where your users take you through their spontaneous behaviour.