Even if AI makes it easier to build competing software, incumbent SaaS giants retain customers due to immense switching costs. The operational disruption, retraining, and integration challenges of migrating a large organization create a powerful moat against new entrants.

In legacy industries like insurance and law, incumbents often claim their advantage is 'relationships.' In reality, this is often a euphemism for high friction and annoyance in switching providers. Customers stick with subpar service not out of loyalty, but because the effort of moving (e.g., finding 40 documents) is too high.

While being a system of record creates high switching costs and ensures retention, it doesn't translate to growth. "Prisoner" customers with no easy alternative are more likely to seek cost reductions from their vendor rather than increase their spend. Growth requires delivering new value, not just leveraging lock-in.

Incumbent software like Workday creates immense stickiness, not through love, but through deep integration and high switching costs. This creates a 'Hotel California' effect where customers 'can check out any time they like, but they can never leave,' a moat that only a 10x better alternative can breach.

True defensibility comes from creating high switching costs. When a product becomes a system of record or is deeply integrated into workflows, customers are effectively locked in. This makes the business resilient to competitors with marginally better features, as switching is too painful.

Ariel Cohen argues that the strongest competitive advantage is a product that employees love. He backs this with a powerful statistic: in Navan's history, only six enterprise customers have ever churned, and five of them later came back, highlighting retention driven by superior user experience rather than contracts.

The most defensible businesses, especially in enterprise software, create such high switching costs that customers are essentially locked in. This "hostage" dynamic, where leaving is prohibitively difficult, is a stronger moat than simply having satisfied customers who could still churn. It's the foundation of an enduring software business.

Platforms like ServiceNow dominate not because they are beloved, but because their initial flexibility allowed customers to build deep, custom workflows. This creates immense stickiness and high switching costs, making it difficult for users to leave even if they are unhappy with the product.

Defensible companies build systems of record (like an ERP) that are so integral to a customer's operations that switching is prohibitively difficult. This creates a 'hostage' dynamic, providing a powerful moat against competitors, even those with better AI features.