The Amazon & Walmart Seller Profitability Checklist

From Internettraffik Seller Services

Most sellers don't lose money on one big mistake. They lose it a few dollars at a time: a fee they forgot, a return they didn't plan for, a "deal" that sat in a warehouse for 90 days. Run every product through this checklist before you buy, and run your top sellers through it once a month.

Part 1: The 60-second profit formula

Net profit per unit = Sale price − Referral fee − Fulfillment fee (FBA/WFS, or your label + packaging for FBM) − Inbound shipping − Prep/labels/bags − Storage (monthly × months held) − Return allowance − Cost of goods

ROI = Net profit ÷ Cost of goods  ·  Margin = Net profit ÷ Sale price

Worked example (illustrative numbers only; always pull current fees for your exact item):

Rule of thumb to start: pass on items under 30% ROI or under $3 net profit per unit, unless they sell very fast and you can rebuy them easily.

Part 2: Before-you-buy checklist

Demand

• It actually sells. Check price and sales-rank history over 90 days, not just today.
• The price is stable. If the price crashed when new sellers showed up, expect it to happen again.
• Competition is manageable. Count the FBA/WFS offers near the Buy Box price. If Amazon or Walmart itself sells it at that price, be careful.

Eligibility and risk

• You're allowed to sell it. Check eligibility in the Seller app or Seller Center before you buy. Look for brand and category gating and hazmat flags.
• No IP red flags. Avoid brands known for filing complaints against resellers.
• Keep your invoice or receipt so you could prove where the item came from if asked.

The math

• You used the fee calculator (Amazon Revenue Calculator / Walmart fee schedule) for the exact item and size tier.
• You counted every line: inbound, prep, storage and returns, not just the referral fee.
• It clears your minimums: ROI and net profit per unit.
• You know how fast it will sell. Slow movers tie up cash and rack up storage fees.

Part 3: Monthly profit health check (top 10 SKUs)

1. Re-run the profit formula with this month's actual fees
2. Flag any SKU whose margin dropped 5+ points
3. Find inventory older than 60 days and decide: reprice, remove, or liquidate
4. Check return rate per SKU, and look into anything over 5%
5. Compare FBA/WFS fees with your own fulfillment cost for heavy or slow items
6. Reconcile payouts against sales: missing reimbursements, lost or damaged inventory
7. Review Account Health: late shipments, cancellations, policy warnings
8. Update your reorder list. Only reorder what's profitable and selling

Part 4: FBA vs FBM vs WFS

• FBA (Amazon ships): best for small, fast-moving, Prime-sensitive items. Watch storage and aged-inventory fees.
• FBM / seller-fulfilled (you ship): best for heavy, oversized, slow or high-value items. Watch shipping-speed metrics and your time.
• WFS (Walmart ships): best for Walmart sellers who want the 2-day badge. Watch storage and inbound prep requirements.

Fee structures change often. Always confirm current fees in Seller Central or Seller Center.

Educational content only. Not financial, legal or tax advice. No income guarantees. Amazon and Walmart are trademarks of their respective owners. Internettraffik is not affiliated with either.