AI features do not have a single unit cost. Some requests are cheap and fast; others require long context, retrieval, reranking, tool calls, or premium models. If you ship AI without tiering, you eventually face one of two outcomes: rising costs or hidden throttling that users hate.
Tiering is a product pattern that makes cost and risk manageable without turning every request into a finance debate.
Define tiers by workflow value and risk
A simple tier structure might look like:
- Standard. Cheap models, bounded context, limited tools.
- Premium. Higher quality models, deeper retrieval, richer citations.
- Regulated. Stronger controls, approvals, and audit-ready evidence (see compliance audits).
Use routing as the enforcement layer
Tiering becomes real when routing is explicit and logged. Route requests based on tier, tenant, workflow, and risk signals, and record why a route was chosen (see routing and failover and decision logging).
Pair tiers with quotas and budgets
Premium tiers need guardrails. Use quotas and rate limits per tenant/workflow to prevent runaway usage and keep fairness (see quotas). For spend control, combine budgeting with anomaly detection and a cost incident runbook (see cost anomaly detection).
Use caching to make premium sustainable
Many premium requests have repeat patterns. Safe caching can reduce cost without reducing quality, but it must be tenant-aware and policy-aware (see caching strategies).
Make cost signals visible in UX
Users accept constraints when they are transparent. Practical patterns include:
- Clear messaging when a request is in "standard" vs "premium" mode.
- Explicit prompts for expensive actions (see user transparency).
- Fast fallbacks when budgets are exceeded, rather than silent quality drops.
Measure unit economics per tier
Tiering is only useful if you can measure it. Track token usage, latency, and outcomes per tier and workflow (see FinOps and chargeback and usage analytics).
Good tiering protects both sides: users get predictable experiences, and organisations keep costs and risk within a sustainable envelope.