Grandfathering

Grandfathering is the practice of letting existing customers keep their old plan and pricing when you change what new customers get. If you raise prices, retire a plan, or re-tier features, grandfathered accounts continue on the terms they signed up under - sometimes indefinitely, sometimes for a defined transition period. It's primarily a trust and retention tool: honoring the deal people bought protects goodwill, reduces the churn spike that a forced price hike triggers, and rewards early adopters who took a chance on you. The cost is complexity and drag. Every legacy price is another tier your billing system, support team, and codebase must maintain, and a large grandfathered base can quietly cap your revenue as your costs (especially variable AI/infrastructure costs) rise underneath fixed old prices. The pragmatic middle path is to grandfather generously but not forever: give clear, well-communicated notice, offer incentives to move to current plans, and set sunset dates so legacy pricing doesn't become permanent technical and financial debt.