Why subscription has a floor that single orders don't
Single-order pricing covers source-account cost plus per-order operational overhead. The operational overhead is roughly $0.40-1.00 per order regardless of size — order validation, dispatch scheduling, refill provisioning. On a 100-like order, that's 0.4-1.0¢ per like. On a 5,000-like order, it's 0.008-0.02¢. Subscription removes the per-order overhead by batching dispatch into a single monthly billing event, which floors the per-like cost at the source-account rate alone.
