What the numbers say
Quantity breaks take a larger share off every unit as the quantity grows: 5% off each for two, 10% for three, 15% for four. Shipping is charged at $9.29, the 1 lb label passed through, so the offer's cost is the discount alone.
One unit keeps $20.25. Four at 15% off keep $70.08, 50.7% of what the customer pays: the four units share one pick-and-pack fee and one parcel, and the label for four weighs in at $10.50.
Against the single, each tier 2 units can lose 50.3%, 3 units can lose 64.2%, 4 units can lose 71.1% of conversion per visitor. Quantity breaks work when they move buyers up a tier, not when they discount the buyers who would have bought four anyway.
Nature's Sunshine's Subscribe & Thrive takes 25% off every subscription order and ships it free. Nature's Sunshine, Subscribe & Thrive, read 23 September 2026
The cost structure, and where it comes from
| Price | $37.95, a bottle of supplements. Nature's Sunshine homepage, read 23 September 2026 |
|---|---|
| Unit cost | $10.47. From the reported gross margin: “Gross margin in 2025 increased to 72.4% compared to 71.5% in 2024.” Nature's Sunshine, fourth quarter and full year 2025 results, read 23 September 2026 |
| Pick and pack | $3.20 per order and $0.48 for each extra item. Fulfill.com, 3PL pricing benchmarks (The Fulfillment Advisor 2025 survey of 600+ warehouses), read 23 September 2026 |
| Shipping label | USPS Ground Advantage, commercial, Zone 5, by weight rounded up to the pound: 1 lb $9.29 · 2 lb $10.50 · 3 lb $12.12 · 4 lb $13.89 · 5 lb $14.53. Packed weight is an assumption: 0.5 lb per unit. USPS Notice 123, USPS Ground Advantage Commercial, Zone 5 (effective 4 October 2026), read 13 October 2026 |
| Card fees | 2.9% + $0.30 per order: Shopify Payments' online rate for a standard card on the Basic plan in the United States. Higher plans pay a lower rate, and premium cards a higher one. Shopify's pricing page for the United States, online standard card rates, read 12 October 2026 Rates by plan and country |
| Refund reserve | 5%, Offer Suite's default assumption for consumables. NRF's all-category figure for online sales is 19.3%, but consumables are rarely returned; use your own rate. |
| Gift | A travel-size bottle: unit cost $5.24, retail $15.00. A half-size bottle, costed at half the full bottle's unit cost. |
The offer, as an agent writes it
An agent writes this offer as one document for Offer Suite's API, validated against the offer schema. Below is one option of it: what the buyer gets and the price it promises. Offer Suite checks with a real cart that checkout charges exactly the prices above.
Show one option 4 options · excerpt
{
"key": "qty-2",
"display": {
"title": "2 units, 5% off each"
},
"lines": [
{
"role": "main",
"quantity": 2,
"purchase": {
"type": "one_time"
}
}
],
"pricing": {
"promise": {
"firstChargeCents": 7212,
"renewalChargeCents": null
}
}
}How Offer Suite validates, versions and publishes a document like this one: offer documents.
Questions
Are quantity discounts profitable for supplement brands?
On these costs one unit keeps $20.25 per order, two at 5% off each keep $40.77 and four at 15% off each keep $70.08. The tiers cost money only on buyers who would have bought the same quantity at full price.
How much conversion do quantity breaks need for supplement brands?
Against one unit, per visitor: 2 units can lose 50.3%, 3 units can lose 64.2%, 4 units can lose 71.1%.