Once product-market fit is achieved, the singular obsession must be retention. Before focusing on expansion metrics like NRR or efficient acquisition (CAC), you must first prove you can stop the "leaky bucket" and keep the customers you've already won.

When evaluating AI companies, focus on customer love (gross retention) and efficient acquisition over gross margins. High margins are less critical initially, as the 99%+ decline in model input costs suggests a clear path to future profitability if the core product is sticky.

Many founders mistakenly define Product-Market Fit by revenue (e.g., "$1M ARR"). The correct measure is the ability to predictably create customer value. This is best quantified by a leading indicator for long-term retention, not sales figures, as revenue can be achieved without true market fit.

Unlike typical apps, ChatGPT users can take months to fully grasp how to delegate various life and work tasks to the AI. This gradual, continuous discovery of new use cases causes previously inactive users to return, creating a rare smiling retention curve.

Counterintuitively, consumer AI apps like ChatGPT show more durable user loyalty than B2B developer tools. Developers can easily swap models via API calls, but consumers build habits and workflows that are harder to change, creating a more stable user base.

Since ChatGPT's launch, OpenAI's core mission has shifted from pure research to consumer product growth. Its focus is now on retaining ChatGPT users and managing costs via vertical integration, while the "race to AGI" narrative serves primarily to attract investors and talent.

Everyone obsesses over Net Revenue Retention (NRR), but Gross Revenue Retention (GRR) is the real indicator of product health. GRR tells you if customers like your product enough to stay, period. A low GRR signals a core problem that expansion revenue in NRR might be masking.

The current AI hype cycle can create misleading top-of-funnel metrics. The only companies that will survive are those demonstrating strong, above-benchmark user and revenue retention. It has become the ultimate litmus test for whether a product provides real, lasting value beyond the initial curiosity.

Only a few applications exhibit 'smile curve' retention, where churned users eventually return due to high utility. ChatGPT is the only AI app to achieve this, placing it alongside foundational platforms like Chrome and WhatsApp. This suggests it's becoming an indispensable tool that is difficult to permanently replace.