Case Study Reducing ACoS and Scaling Sales for an Amazon Seller
How a US Amazon 3P seller cut ACoS to 4.2% and scaled monthly orders to 1,256 through PPC optimization.
4.2%
ACoS achieved
~1,256
Monthly orders generated
21.59
Return on Ad Spend (ROAS)
The Client
A growing B2C retailer seeking to scale their Amazon channel.
The client is a US-based Amazon third-party (3P) seller offering a range of consumer goods. Operating in a highly competitive e-commerce landscape, they managed their storefront directly via Amazon Seller Central. While they had established a baseline of organic sales, they had limited in-house expertise in Amazon's advertising network (Sponsored Products, Brands, and Display).
As Amazon's search results have become increasingly paid-dominated, the client realized that scaling their channel required a structured paid search strategy. However, their early attempts at PPC advertising were managed ad-hoc, with little keyword structure or negative match targeting.
Facing rising competition and a constrained advertising budget, the client needed a partner to audit their ad account, restructure their bidding, and build a sustainable PPC pipeline that could drive sales without depleting margins.
The Challenge
High ad costs and low returns on a constrained budget.
When we took over the account, the client’s Amazon PPC campaigns were running at a high Advertising Cost of Sales (ACoS) of 8.25%. While ad spend was increasing monthly, conversion rates remained low, resulting in low ROAS and thin margins.
The primary issue was an inefficient campaign setup. Ad groups contained hundreds of mixed keywords, auto-campaigns were left unmonitored, and budgets were distributed without prioritizing high-converting products. Additionally, the client did not use negative keyword matches, causing their ads to trigger on unrelated, high-volume search queries. With a constrained budget, the client needed to improve profitability quickly to avoid suspending paid ads.
8.25%
Baseline Advertising Cost of Sales (ACoS) at engagement start.
~1,000
Average monthly orders generated prior to optimization.
Unoptimized ACoS of 8.25% reducing product margins.
Inefficient campaign setups with hundreds of keywords in a single ad group.
Budget waste due to a lack of negative keyword targeting.
A constrained advertising budget requiring immediate ROAS improvements.
What our audit found
Identifying broad matching issues and low-converting listings.
Our diagnostic phase began with an audit of the ad account history, search term reports, and product detail pages (PDPs). We found that over 60% of ad spend was being consumed by broad-match keywords that were too generic to drive buying intent, such as "kitchen gadgets" rather than product-specific terms.
Additionally, we identified a conversion leak on the product listings themselves. The detail pages lacked optimized copy, secondary images, and clear benefit callouts. This meant that even when ads successfully drove clicks, visitors bounced without buying, lowering the listing’s organic quality score and increasing click costs. The diagnostic confirmed that optimization required both search query filtering and listing improvements.
Over 60% of ad spend wasted on broad-match, low-intent terms.
A lack of negative keywords, causing budget waste on irrelevant searches.
Poorly optimized listings with weak imagery and copy, lowering conversion rates.
Scattered budgets across low-margin SKUs instead of focusing on top-selling products.
The Solution
How we turned it around.
Adjusting CPC bids and purging negative keywords.
To stabilize ACoS, we began by optimizing the keyword targeting. We extracted search term reports to identify non-converting, high-cost search queries and added them as negative exact and negative phrase matches across all active campaigns.
In parallel, we restructured the bidding logic. We transitioned from generic broad-match targeting to structured exact-match and phrase-match campaigns. We adjusted CPC bids based on historical performance, lowering bids on low-converting keywords and increasing bids on high-intent, product-specific search terms. This ensured the ad budget was directed toward high-probability sales.
What we shipped
- Standardized negative keyword audits to eliminate non-converting clicks.
- Reallocated budget to exact-match and phrase-match keywords.
- Dynamic bid adjustments based on historical search term performance.
Pausing low-performing campaigns and optimizing budgets.
With a constrained ad budget, we had to focus spend on the client's most profitable products. We audited the campaign portfolio and paused underperforming campaigns that were driving high ACoS with low conversion rates.
We consolidated the remaining budget into targeted campaigns for the client's top-performing SKUs. We established daily budget controls to prevent high-volume, low-converting keywords from depleting the budget early in the day. This budget restructuring ensured the client's top-converting products maintained ad coverage during peak shopping hours.
What we shipped
- Underperforming campaigns driving high ACoS paused.
- Budgets consolidated into high-margin, top-performing product campaigns.
- Daily budget caps and pacing controls implemented to maintain coverage.
Upgrading product detail pages for conversion.
Recognizing that driving traffic is only half the battle, we audited and upgraded the client's product detail pages (PDPs). We optimized product titles, bullet points, and descriptions with target keywords to improve both organic visibility and ad relevance.
We also worked with the client to upgrade their listing images. We replaced low-quality product photos with high-resolution imagery, lifestyle photos, and infographics that highlighted product features. This improved the listing's conversion rate, raising its organic search ranking and lowering the CPC for corresponding ad campaigns.
What we shipped
- Keyword-rich titles and descriptions optimized for relevance.
- Product images upgraded to include lifestyle photography and infographics.
- Improved conversion rate, leading to lower ad costs and higher organic visibility.
Ongoing monitoring and keyword expansion.
Once we stabilized the core campaigns, we established a weekly optimization cadence to scale performance. We monitored search term reports to identify new search queries and launched them in targeted exact-match campaigns.
We implemented automated bidding rules to adjust bids based on hourly performance, ensuring competitiveness during high-traffic periods while reducing bids during low-converting hours. This ongoing keyword expansion and bidding adjustment allowed the client to grow order volume within their budget constraints.
What we shipped
- Weekly search term audits to capture new keyword opportunities.
- Bidding rules configured to adapt to traffic cycles.
- Keyword expansion to capture long-tail search intent.
The Numbers
Outcomes we can talk about.
Within six months of starting the optimization sprint, the client's Amazon advertising performance improved significantly. The target ACoS dropped from 8.25% to a stable 4.2%, exceeding the client's initial goals and preserving margins.
By concentrating budget on top-performing campaigns and optimizing listings, monthly order volume grew from ~1,000 to ~1,256. This order growth was achieved on a highly efficient budget, as reflected in the ROAS of 21.59.
The combination of ad optimization and listing improvements also boosted the listings' organic rankings. This generated a steady flow of organic, non-paid sales, establishing a sustainable foundation for the brand's long-term growth on Amazon.
4.2%
ACoS achieved
~1,256
Monthly orders generated
21.59
Return on Ad Spend (ROAS)
What We Built
What's Next
Scaling with Amazon Sponsored Brands and off-platform attribution.
With a stable PPC engine in place, we are preparing to expand the advertising program into Amazon Sponsored Brands and Sponsored Display campaigns. This will allow the client to target competitor listings and build brand awareness.
We are also planning to implement Amazon Attribution to track and optimize off-platform traffic from social media and search engines. This multi-channel expansion will help scale sales while maintaining target ACoS and ROAS thresholds.
Frequently Asked Questions
About This Project
The questions teams usually ask when they want to run a similar engagement.
ACoS stands for Advertising Cost of Sales. It is calculated by dividing total ad spend by total ad-generated sales. In this campaign, we reduced ACoS from 8.25% to 4.2%.
The Real Numbers
Need real numbers? Let's talk.
We kept the names off the page. The story is real, the outcomes are real, and we're always happy to walk a serious team through the rest of it.
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