Deepening Customer Lock-InWide moat

The installed base is the mechanism by which ASML's customer relationships deepen into something close to permanent. A leading-edge fab contains dozens or hundreds of ASML machines, each dependent on ASML for service, spare parts, software, and upgrades over a decade or more of operating life. The customer is not merely buying a product; they are entering a multi-decade relationship in which ASML is woven into the daily operation of their most critical, most expensive production capacity. That is lock-in of the deepest kind — not a contract or a switching cost, but an operational dependence that grows with every machine and every year.

This lock-in reinforces every other part of the moat. It makes the service annuity durable, because the customer cannot leave; it strengthens ASML's position in selling the next generation of machines, because the customer's fab, workforce, and processes are already built around ASML; and it raises the cost of any customer ever attempting to qualify an alternative, even if one existed. The relationship compounds: the more ASML machines a customer runs, the more dependent they become, and the more natural it is to buy the next machine from ASML too. In a business already protected by a technology monopoly, the installed base adds a second, relationship-based moat — binding the world's most advanced chipmakers to ASML not just because they must, but because, after years of running its machines, they are wholly built around it — a dependency the sole-supplier position makes absolute at the leading edge¹.