What a threshold does
A free shipping threshold is a rule that waives the delivery charge once an order reaches a set value, such as free delivery on orders above 50. The intent is simple: give shoppers a reason to add a little more to the basket so that they cross the line. For the shopper the offer is easy to understand. For the business it changes the mix of orders, the average order value and the amount of shipping cost it carries itself.
Nothing in this approach is guaranteed to pay off. Whether it does depends on margins, customer behaviour and the actual cost of shipping the orders involved.
Who pays for “free” shipping
Shipping is never free to the business; the carrier still sends an invoice. Free shipping simply moves the cost from the customer to the seller, who recovers it from product margin, higher prices, or the extra profit from larger baskets. In practice, the cost is absorbed in one or more ways:
- Margin. The seller accepts a lower profit on orders that qualify.
- Product prices. Prices are set slightly higher to include some delivery cost.
- Larger baskets. The extra items bought to reach the threshold generate additional gross margin, which covers the shipping.
- Other customers. Where shipping charges for smaller orders are kept above cost, they partially fund the free ones.
Deciding which of these is doing the work is the core of the analysis.
A simple margin example
Assume a store earns a 35 percent gross margin on products and that delivery costs it 5 per order, whatever the size, to keep things simple.
- A 50 order earns 50 x 0.35 = 17.50 in gross margin. If shipping is free, subtracting 5 leaves 12.50.
- A 40 order, where the customer pays the 5 delivery fee, earns 40 x 0.35 = 14.00, and the shipping charge exactly covers the cost.
On a per-order basis, the 50 order with free shipping earns less (12.50) than the 40 order with paid shipping (14.00). A threshold at 50 therefore only improves profit if it brings in extra orders, or lifts enough baskets from below the line to above it, to outweigh this difference. If customers who would have spent 60 anyway now get free delivery, the store simply gives away money. The numbers are invented for illustration. Use your own margin and cost per parcel.
How thresholds affect behaviour
Common patterns that stores report, and that are worth checking in your own data:
- Order values cluster just above the threshold. Shoppers often add a small item to reach it.
- Some shoppers abandon rather than add. If the gap is large, they may leave or look elsewhere.
- Orders may get larger but less frequent. Some customers wait to combine purchases.
- Heavy items change the picture. A threshold based on value ignores weight, so a low-value heavy product can cost more to ship than it earns.
These effects differ widely between product categories and audiences.
Choosing a level
There is no standard answer, but a few ideas help.
- Start from average order value. A threshold modestly above the current average tends to encourage a small increase. Set far above the average, it may be out of reach for most customers and act as noise.
- Check margin at the line. Calculate gross margin minus shipping and handling cost for orders just above the threshold. If it is negative, the threshold is too low or the offer too wide.
- Account for shipping variation. Orders going long distances or to rural delivery areas can cost much more than average. Some stores exclude certain regions or heavy products from the offer, or use a regional threshold.
- Consider the comparison point. What the shipping charge would otherwise be matters. The decision interacts with flat rate shipping and calculated shipping, so review them together.
- Allow for returns. Free outbound shipping combined with free returns can multiply cost, and some orders are inflated to reach the threshold and then partly returned. Prepaid return labels and return fraud are covered elsewhere.
Alternatives to a blanket threshold
- Discounted shipping instead of free, such as a reduced rate above a lower line.
- Free shipping for a membership or subscription, where a fee or commitment offsets the cost.
- Free delivery to pickup points and lockers, which is often cheaper for the carrier.
- Product-level free shipping, applied only to items with healthy margins.
- Time-limited offers, which let you test the effect without a permanent commitment.
Testing
A threshold can be tested like any pricing decision. Record average order value, order count, conversion at the shipping step, shipping cost per order and gross margin after shipping, before and after the change. Change one thing at a time, allow enough orders to accumulate, and be careful about seasonal demand, which can look like an effect of the threshold when it is not. Review the numbers after any of the yearly rate increases, since a higher carrier cost can turn a profitable level into a loss-making one.