Recurring delivery programmes offer a modest discount in exchange for a standing order. The reduction is small because what the seller gains is predictability rather than volume.
Forecasting is worth paying for
A seller who knows how many units will ship next month can order production, book warehouse space and negotiate freight with far more accuracy than one guessing at demand.
Errors in that forecast are expensive in both directions, producing either stockouts that lose sales or excess inventory that accrues storage charges.
A subscription base converts part of the guesswork into a known quantity, and the discount is what that certainty costs.
The discount scales with commitment
Programmes typically increase the reduction when several items ship together on the same schedule, because a combined delivery costs less to pick and pack than separate ones.
Consolidating shipments also reduces packaging and transport per item, so the deeper discount is funded by a genuine saving rather than by margin sacrifice.
This is why the largest reductions require a threshold number of subscriptions arriving in one delivery rather than simply a larger order.
Prices are not fixed by the subscription
The discount is a percentage applied at the time of each shipment, not a locked price, so the amount charged moves with the underlying listing.
An item can therefore become more expensive over successive deliveries while the discount percentage remains unchanged and the arrangement still looks favourable.
Checking the charged amount rather than the discount rate is the only way to see what is actually happening to the cost.
Cancellation friction is part of the model
Recurring orders continue until someone stops them, and the effort required to review a schedule exceeds the effort required to leave it alone.
Households accumulate subscriptions for consumables they no longer use at the same rate, and the surplus sits in a cupboard rather than prompting a review.
Programmes send reminders before each shipment because regulation and reputation both require it, though a reminder still relies on the recipient acting.
Where the arrangement pays off
Consumables with steady, predictable use match the model well, since the delivery interval can be set close to the real consumption rate.
Items used irregularly do not, because the schedule imposes a rhythm that the household does not actually follow.
Reviewing the schedule against what has been consumed, rather than against what was ordered, is the check that keeps the arithmetic honest. A cupboard holding several unopened deliveries is the clearest evidence that the interval is wrong.