The logic behind a free tier is straightforward. Lower the barrier to entry, increase the top of the funnel, convert a percentage of free users to paid. The math works in theory and fails in practice for a specific reason.
Free users and trial users are not the same population. A trial user has made a time-limited commitment to evaluate the product. There is a natural endpoint that creates urgency. A free user has made no commitment and faces no endpoint. The evaluation never has to conclude.
The behavioral pattern that shows up is that free tier users engage with the product at a surface level, derive partial value, and remain on the free tier indefinitely. They are not unconverted paying customers. They are a separate segment that was never going to pay at the price point offered. The product solved enough of their problem for free that the upgrade case never became compelling.
The companies that run this successfully are the ones where the free tier is genuinely limited in a way that creates a specific, felt constraint. Not artificially limited with features removed, but limited by the natural ceiling of what a non-paying user actually needs. When a free user hits that ceiling on a task that matters to them, the conversion event is obvious. When the free tier is generous enough to satisfy most use cases, the ceiling never arrives.
The trial model with a hard end date and full feature access consistently outperforms the freemium model for B2B SaaS below $500/month ACV. The urgency is structural rather than manufactured.