Reserved / prepaid contracts
A customer can pay you up front to lock in a discount for 6 to 12 months. You get a chunk of cash today and a predictable revenue line you can plan around; they shave roughly 25% off the rate in exchange for committing. It's a genuine win-win — steady money for you, a cheaper bill for them.
A reserved deal locks both sides in: you can't drop the customer, and they can't walk away until the term ends. That stability is the whole point — but it means the capacity is spoken for. Sell reservations against servers you don't actually have, and you've turned a comfortable cushion into an over-promise you have to scramble to honor.
Detailed explanation
Modeled as Contract::Reserved { discount_pct, until, prepaid_revenue }. Defaults: 25% discount, a 5x signup-bonus prepay landing as cash at signing, and a 6-month term (12 months for anchor tenants). The reservation locks_churn until expiry, so the engine will neither let the customer lapse nor let you evict them for the duration.
Prepaid revenue smooths your cash curve but pins committed capacity for the term, so reserved load is the floor you must always have headroom above. Treat the reserved book as non-negotiable demand when you reason about error budgets and SLA exposure — those customers can't leave, which means a breach against them is a refund you can't churn your way out of.