One of the key insights behind the success of Visa was that, by the late twentieth century, money had become data:

Realization slowly dawned that money had become alphanumeric symbols recorded and transported on valueless metal and paper. This still left a gap in understanding, for symbols themselves had no value. Anyone would write down letters and numbers; printing presses and computers could spew out infinite quantities. Money had become guaranteed alphanumeric data expressed in the currency symbol of one country or another. Thus, a bank would become no more than an institution for the custody, loan, and exchange of guaranteed alphanumeric data. (p. 95; emphasis in original)

This insight built upon the earlier technology of double-entry accounting, and was a natural stepping stone along the path toward the ideas in the Bitcoin white paper.

When money became alphanumeric data, then the Visa network took on three purposes:

Was credit really the nature of our business? What was the essence of the transaction when a customer presented a sliver of plastic to a merchant? [Their credit card] was a substitute for a driver’s license, social security card, government identity card, or other means of identification. Thus, the first function of the card was to identify buyer to seller and seller to buyer….

The seller would receive good funds in local currency and the buyer would be billed later in the currency of their country. Thus, the second primary function was as guarantor of the value data….

The fact that many card issuers allowed the customer to pay for the transactions over a period of time… was really an ancillary service and not the primary function of the card…. [T]he third primary function was origination and transfer of value data. (p. 97-8, emphasis in original)

Visa benefitted from the fact that all three functions were able to reach global scale using the information technology available at the time. Beyond the insights listed here, the story of this book is one of an organization and its founder who found themselves in the right place at the right time. Readers of this book might also enjoy a more detailed history of Visa in VISA: The Power of an Idea.