Seller and vendor advertising need different business inputs even when the campaign formats look similar. A seller manages its marketplace offer and selling economics; a vendor supplies Amazon Retail and must coordinate with its wholesale economics and retail availability. Do not compare their ACoS targets without reconciling the revenue basis.

Start with the economic model

Decision	Seller / 3P	Vendor / 1P
Contribution	Selling revenue less applicable product and marketplace costs	Wholesale economics and applicable commercial costs
Offer changes	Seller controls its own offer within marketplace rules	Retail price and availability require coordination with Amazon Retail
Inventory review	Saleable offer stock and replenishment	Retail availability, supply and purchase-order context
Reporting	Seller and advertising reports	Vendor and advertising reports

Confirm the definitions used by the actual account. An advertising sales field may not match the revenue on which the business earns its margin. Applying a wholesale margin percentage directly to a retail-sales denominator can misstate break-even.

Seller playbook

Before scaling traffic, check price, delivery, stock and Featured Offer status for the exact offer. Review product-level contribution and use it to bound bids. When eligibility is lost, inspect the cause instead of increasing bids or applying an arbitrary universal percentage rule. Amazon Featured Offer guidance.

Separate campaigns where products have materially different economics or stock constraints. Record changes to pricing and fulfilment so performance comparisons have context.

Vendor playbook

Coordinate advertising with retail availability and replenishment expectations. An open purchase order is not proof that stock is ready for shoppers. Identify who can resolve availability, detail-page and commercial issues, and keep those responsibilities distinct from the advertising operator.

If the campaign reports retail attributed sales while your planning uses wholesale contribution, build a documented reconciliation at the product level. Do not infer vendor profit from ROAS alone. Track the supply constraint and the advertising constraint separately.

Choose formats by objective and eligibility

Sponsored Products can support product discovery; Sponsored Brands provides brand-oriented creative and supported destinations. Display choices depend on the available campaign setup. Neither the seller nor vendor label dictates a universal allocation.

Amazon lists separate eligible advertiser types for Sponsored Brands. Sponsored Brands eligibility. Amazon DSP is available even to advertisers that do not sell on Amazon, so a vendor contract is not a prerequisite or an automatic DSP entitlement. Amazon DSP.

Align measurement before comparing

Record campaign type, seller/vendor role, sales definition, attribution scope, currency and export time. Amazon's conversion guidance distinguishes reporting definitions and windows; recent sales may be incomplete. Amazon conversion metrics.

Hypothetical budgeting exercise: if a product group provides £4,000 contribution before advertising and the business wants to retain £1,500, its simplified advertising allowance is £2,500. Confirm that the contribution and advertising period describe the same scope. That monetary allowance is more useful than importing a seller's ACoS target into a vendor account without reconciliation.

Shared operating checklist

Assign one advertising owner, a retail issue owner and a replenishment contact. Save current settings before approved changes and verify the resulting provider state. Document stock and promotion events alongside results. If data is unavailable, mark it unknown rather than assuming zero sales or zero inventory risk.

Is moving to Vendor a way to unlock better ads?

Evaluate the commercial relationship on its own terms. Advertising access has separate requirements, and no model guarantees better sales. Use format comparison and dashboard definitions to plan the actual operation.

Related Arctavia resources

Use these supporting pages to compare Amazon PPC operating models and implementation choices.

• Amazon Ad Rejections: Check Claims, Images and Destinations
• Amazon Ads ACoS Suddenly Increased: What to Check First
• Amazon Ads ML Bid Review: Guardrails Before Aggression
• Amazon PPC Automation: Data, Decisions and Operating Controls
• Amazon PPC Automation Migration Checklist
• Amazon PPC Automation vs Agency: Which Operating Model Fits Better?