Published: 21st July 2026
A weak Amazon ROAS is rarely fixed by one bid reduction. If you want to know how to improve Amazon ROAS, start by separating inefficient spend from investment spend. The former burns budget without building profitable sales. The latter may carry a lower immediate return while winning high-value keywords, defending branded demand or launching a product with genuine potential.
The commercial mistake is treating ROAS as an isolated advertising metric. Amazon advertising performance is shaped by campaign structure, retail readiness, organic ranking, stock position, price, competitor activity and repeat purchase behaviour. Cut bids blindly and ROAS can rise while total profit and market share fall. Scale aggressively without control and revenue rises while contribution disappears.
The objective is not the highest possible ROAS. It is profitable, repeatable growth at a return your business can afford.
ROAS means advertising revenue divided by ad spend. Spend £1,000 and generate £5,000 in attributed sales, and your ROAS is 5.0. Useful, but incomplete.
Your acceptable ROAS depends on gross margin, Amazon fees, fulfilment costs, promotions, VAT treatment, returns and the role of the product in your wider catalogue. A 4.0 ROAS may be excellent for a high-margin consumable with strong repeat purchase. It may be commercially unacceptable for a low-margin bulky item with high fulfilment fees.
Set targets by product group, not at whole-account level. A hero SKU, a new launch and a clearance line should not be managed to the same return threshold. This is where many accounts lose control: the blended number looks healthy, but profitable products are subsidising campaigns that should have been rebuilt or stopped weeks ago.
Use three practical classifications:
This creates a better conversation than asking whether a campaign is good or bad. Every pound of spend should have a job.
Amazon ads amplify the offer customers see. They do not rescue an uncompetitive listing.
Before tightening bids, inspect the retail fundamentals on every advertised ASIN. Is the main image immediately clear on mobile? Does the title answer the shopper’s core question? Are the price, voucher and delivery promise competitive against the results around it? Is the product in stock, Prime-eligible where appropriate and carrying enough credible reviews?
Conversion rate is one of the biggest ROAS levers because it changes what you can afford to bid. If a product converts at 10% rather than 5%, the same click has twice the chance of generating a sale. That gives you more room to defend key terms, scale Sponsored Brands activity and compete during peak periods.
Do not assume a low-converting ASIN has an advertising problem. Check whether the search term is relevant, then compare the listing directly with the top competing offers. A premium price can work, but the page must make the premium visible through better imagery, stronger proof, clear differentiation and a credible brand proposition.
Stock is equally commercial. Spending to rank an ASIN that will run out of stock damages momentum and forces you to rebuild visibility later. Pacing advertising around inventory cover is not operational housekeeping. It is ROAS management.
Poor structure hides waste. A single broad campaign containing dozens of products, loose match types and one shared budget makes it difficult to see which search terms deserve investment.
A controlled account separates discovery from harvesting. Auto, broad and phrase activity are useful for finding customer language and ASIN opportunities. Exact match campaigns then give proven terms their own bids, budgets and performance targets. Product targeting should be separated from keyword targeting because the intent, conversion rate and competitive context are different.
Sponsored Products remains the core performance engine for most brands, but Sponsored Brands and Sponsored Display should not be judged by identical rules. Sponsored Brands can protect category visibility and direct shoppers to a Store or product collection. Sponsored Display can support remarketing and competitor-ASIN conquesting. Both may show a different attribution profile from bottom-funnel Sponsored Products.
The point is not to create an elaborate account for its own sake. It is to give each campaign a defined role and enough budget clarity to make decisions.
Search-term reports tell you what customers actually typed before clicking. That is where wasted spend becomes visible.
Move converting, relevant search terms into exact match campaigns when they have enough sales to justify dedicated control. Add negative exact terms to stop discovery campaigns competing with your proven keyword campaigns. Use negative phrase sparingly, as it can block useful long-tail traffic if applied too broadly.
For non-converting terms, avoid reacting after a handful of clicks. The right threshold depends on your conversion rate and average order value. If your typical product converts one in ten clicks, a search term with 30 or 40 clicks and no orders deserves scrutiny. A term with six clicks and no sales may simply need more data.
This is why a disciplined optimisation process beats daily bid fiddling. Decisions need evidence, not anxiety.
A generic keyword can attract research-led shoppers, while a highly specific long-tail term may signal a buyer ready to purchase. They should not receive the same bid simply because they sit in the same campaign.
Raise bids where a target is profitable, budget-limited and strategically valuable. Reduce bids where it is spending beyond its allowable level, but do it in measured steps so you can see the effect. Large changes can damage placement, ranking and conversion volume before the data has time to settle.
Placement reports matter here. Top of Search often converts better, but the premium is only justified if the incremental sales support it. A blanket placement multiplier is a common source of inflated cost. Review placement performance by campaign and product type, then apply adjustments where the numbers support them.
Also distinguish branded from non-branded activity. Branded search campaigns often deliver exceptional ROAS because shoppers already know the brand. Keep defending that demand, especially where competitors bid on your name, but do not use branded efficiency to hide poor non-branded acquisition performance. Report them separately.
Amazon attribution is useful, but it is not the whole commercial picture. Advertising can generate organic rank, lift conversion through review momentum and support sales across related products. Equally, a strong advertised-sales ROAS can conceal cannibalisation if you are paying heavily for purchases that would have happened organically.
Track total sales, organic sales, TACoS, contribution margin and inventory alongside ad ROAS. TACoS – total ad spend divided by total Amazon sales – gives a clearer view of whether advertising is becoming more or less dependent as the business grows.
A rising ROAS with falling total sales is not automatically a win. A slightly lower ROAS combined with stronger organic revenue, stable margin and growing category share may be the better outcome. The answer depends on your commercial objective, lifecycle stage and available cash.
Promotions need the same discipline. A voucher may reduce conversion friction and improve ad efficiency, but it also reduces margin. Measure the incremental sales and profit, not just the higher conversion rate during the promotion window.
High-performing accounts do not rely on occasional clean-ups. They operate to a clear rhythm: weekly search-term and budget decisions, fortnightly bid and placement reviews, and monthly assessment of profitability, catalogue priorities and stock risk.
Document why material changes are made. When performance shifts, you need to know whether the cause was a bid change, a price move, a competitor entering the auction, an out-of-stock period or a seasonal change in demand. Without that record, teams repeat work and mistake correlation for causation.
For brands without a senior Amazon owner, this is often the missing layer. Accendo360 approaches Amazon advertising as a commercial growth system, not a dashboard exercise: audit the leakage, set the profit guardrails, build the architecture and hold performance to account.
The next useful action is not to reduce every bid. Choose your five highest-spend ASINs, calculate the return each one actually needs, then identify whether the biggest constraint is traffic quality, conversion or margin. That diagnosis will tell you where the next pound should go.