Nik Storonsky, Revolut's founder, had a specific frustration: as someone who traveled frequently for work, he was paying 3-5% currency conversion fees on every transaction abroad. He calculated that this cost him thousands of pounds per year. He assumed millions of other frequent travelers had the same problem.
He was right. But what makes Revolut's story instructive for founders is not the idea — it is the scope discipline. Storonsky and co-founder Vlad Yatsenko built only the prepaid card with real exchange rates. Nothing else. The app was a single-use tool: top up, and spend abroad at the real rate. The design was functional but not remarkable. The features were one, not many.
This focus on one painful problem, solved completely, for one specific type of user (frequent travelers and international workers) created product-market fit that spread through word of mouth. Users told colleagues. Colleagues signed up. The referral loop worked because the product delivered on exactly one promise, reliably and repeatedly.