How did ProtonMail differentiate itself from competitors?
ProtonMail set itself apart by offering end-to-end encryption, meaning that only the sender and recipient could read the emails. This was a significant unique selling proposition (USP) in a market dominated by providers like Gmail and Yahoo, which do not offer the same level of security. By focusing on a niche but growing demand for privacy, ProtonMail was able to carve out a unique space in the crowded email market.