Free Shipping vs Discount: Which One Actually Costs You Less
Unico Commerce, FounderFree Shipping vs Discount: Which One Actually Costs You Less
It's the oldest question in ecommerce incentives: should you offer free shipping or a percentage off? Most answers compare face value and get it wrong.
Here's the reframe: compare them by incremental cost, not by what they look like on the tag.
What shoppers actually respond to
The demand for free shipping is not subtle:
- 94% of shoppers say free shipping drives their purchase decisions.
- Two in three abandon when shipping costs over $10.
- 81% say they'll spend more to qualify for a free-shipping threshold.
A percentage discount is a nice-to-have. Free shipping, for many shoppers, is closer to a dealbreaker. That perception matters before any math does.
The face-value trap
A $6 shipping fee on a $50 order looks like 12% — bigger than a 10% discount. So the naive read is "free shipping costs more."
But that compares the customer's savings. You need to compare your cost.
Incremental cost is the real comparison
A sitewide 10% discount costs you 10% of margin on every single order it touches.
Free shipping above a threshold costs you $0 on any order already over the threshold. You only pay it on orders that (a) are below the threshold and (b) the offer convinces to buy or to top up.
And the threshold does something a percentage discount can't: it raises the basket. A shopper at $42 with a $50 free-shipping threshold will often add an item to clear it. A percentage discount gives no reason to add anything.
The math, side by side
Say shipping costs you $6, and you're choosing between "10% off everything" and "free shipping over $60."
Assume 1,000 orders, AOV $55, margin 55%:
| 10% off sitewide | Free shipping over $60 | |
|---|---|---|
| Margin cost | 10% × $55 × 1,000 = $5,500 | Only on sub-$60 orders that qualify |
| Basket effect | Slightly lower AOV | Pushes some baskets up to $60 |
| Cost on orders already over $60 | Still 10% each | $0 |
If 40% of orders are already over $60, free shipping is free on all of them — while the discount still taxes everyone and gives the over-threshold shopper nothing they needed.
When each one wins
- Free shipping wins on low-AOV, low-intent, or comparison-shopping traffic — where the shipping fee is the actual blocker. It also wins when your AOV sits just below a natural threshold.
- Percentage discounts win on high-AOV or considered purchases, where a shipping subsidy is trivial next to the price and a percentage feels like a real event.
- Neither should be storewide. The same shopper who needs free shipping to convert is not the same shopper who responds to 10% off.
The real answer: decide per shopper
The mistake is treating this as a storewide policy question. It's a decision-level one.
- A shopper hesitating on shipping cost → free shipping clears the block.
- A shopper hesitating on price → the smallest discount that moves them.
- A shopper stuck on neither → lead with the product or bundle most likely to convert, rather than an incentive at all.
That's not a setting in your shipping panel. It's a real-time decision at the moment of hesitation — and it's exactly where the incentive should be chosen.
The takeaway
Stop comparing free shipping and discounts by face value. Compare by incremental cost:
A sitewide discount taxes every order. Free shipping above a threshold taxes almost none of them, and it raises the basket while it works.
The cheapest incentive isn't the one that looks smallest — it's the one you only pay when it actually changes a decision.
