Tailscale's free plan remains free due to the company's careful management of scaling costs, which are kept low by a hybrid centralized/decentralized architecture. The company's business model relies on word-of-mouth and viral growth, with free users serving as a marketing channel for paid corporate plans. Tailscale's founders emphasize their commitment to privacy and transparency, stating that users are not the product. The company's goal is to make the internet better for everyone, not just large corporations.