Amazon FBA vs FBM: which is actually more profitable?
Every Amazon seller eventually faces the same fork: let Amazon handle storage and shipping (FBA — Fulfillment by Amazon), or do it yourself (FBM — Fulfillment by Merchant). The right answer is not universal — it depends on your product's size, price, and how fast it sells.
What you're really comparing
FBA means Amazon stores your inventory, picks and packs orders, ships them with Prime speed, and handles most customer service. In exchange you pay fulfillment fees (by size/weight) and storage fees, on top of the standard referral fee.
FBM means you store and ship everything yourself. You avoid FBA fulfillment and storage fees, but you take on the labor, packaging, shipping costs, and service — and you usually lose the automatic Prime badge that drives conversions.
The fee math
Both models pay Amazon's referral fee (typically 15%). The difference is fulfillment:
| FBA | FBM | |
|---|---|---|
| Referral fee | ~15% | ~15% |
| Fulfillment | Amazon's per-unit fee | Your own shipping cost |
| Storage | Monthly + long-term | Your own / none |
| Prime badge | Yes | Only via Seller-Fulfilled Prime |
For a small, light, fast-moving product, FBA's fulfillment fee is often cheaper than what you'd pay to ship yourself — and the Prime badge lifts conversion. For large, heavy, or slow-moving items, FBA storage and size-tier fees can quietly erode your margin, and FBM may win.
Whichever you're modeling, plug the numbers into the Amazon FBA Profit Calculator to see your real margin and ROI per unit.
When FBA wins
- Small, light products that fit cheap size tiers
- High sales velocity (low storage exposure)
- You value Prime conversion and hands-off logistics
When FBM wins
- Large or heavy items with steep FBA fulfillment fees
- Slow movers that would rack up storage fees
- You already have cheap shipping and warehouse capacity
The bottom line
FBA buys convenience, speed, and the Buy Box edge — and for small, fast-selling products it's often cheaper once you account for what shipping yourself really costs. For bulky or slow inventory, run both scenarios before committing. Start with the Amazon FBA Profit Calculator, then compare it against your own FBM shipping costs.