This article studies the genesis and early international expansion of the bank-issued credit card—an American innovation that quickly took hold in western Europe. Empirical evidence undermines the proposition of a single firm building a proprietary network. In fact, it was a constellation of participants that combined three characteristics, namely, a critical mass of both retail customers and retail merchants; the capacity to implement new technological solutions; and the ability to forge resilient collaborations across national borders. The evidence supports the value of collaboration in retail financial services as means of appropriating network externalities. Moreover, other conceptual and empirical studies, especially those based on two-sided markets, neglect the greater implications that initial conditions in this industry have on long-term success.