Zuora
A subscription billing platform whose founder coined "the subscription economy" and then wrote the book on it.
Tien Tzuo, one of Salesforce's early executives, founded Zuora in 2007 with K.V. Rao and Cheng Zou. The insight was that ERP systems were built to sell a thing once, while SaaS companies sold the same thing every month, complete with upgrades, downgrades, trials and proration. Zuora tracks the contracts, works out the invoice and hands the charge to a payment gateway.
It went public on the NYSE in 2018, the same year Tzuo published Subscribed. In 2024 Silver Lake and GIC took it private for around $1.7 billion, a modest sum for the company that taught the world a toothbrush can be a subscription.