The card reader that plugs into a phone jack changed small business commerce in ways that are easy to underestimate. iZettle was one of the companies that made it happen. Founded in Stockholm in 2010, it brought affordable card acceptance to the kinds of businesses — market traders, food trucks, independent retailers — that had previously been locked out of card payments by the cost and complexity of traditional terminals. Its small, square card reader and clean app arrived in Europe before Square had expanded beyond the US, and iZettle built a loyal user base across a dozen markets before Paypal acquired it for $2.2 billion in 2018 — at the time the largest European fintech acquisition on record. The product lives on within PayPal's commerce platform, but iZettle's legacy is the market it helped create: a generation of small business owners who expect payment infrastructure to be simple, mobile-first, and fairly priced. That expectation has reshaped the entire merchant acquiring industry.