Customer Success emerged as a distinct function in the subscription economy, where revenue is recognised over time and customer lifetime value is determined by retention and expansion rather than initial purchase. Earlier, sales teams handled what is now customer success; the specialisation arose because the time horizon over which customers must experience value shortened dramatically in as-a-service models. Customer Success differentiates from sales in time orientation (longer), goal orientation (adoption and outcomes rather than account closure), and interpersonal orientation. It is one of the three core functions RevOps integrates, alongside marketing and sales.