Why is my ACoS so high on Amazon?

High ACoS is usually caused by one or more of the following: advertising on keywords that are too broad or not specific enough to your product, a listing that does not convert the traffic your ads are sending (poor images, weak title or bullet points that do not address the shopper's intent), bids that are too high for the conversion rate your listing achieves, or a campaign structure that mixes well-performing and poorly-performing keywords under the same bid settings. Check your search term report first for non-converting spend, then review your listing's conversion rate as a separate issue.

Does lowering bids always reduce ACoS on Amazon?

Not always. Lowering bids reduces your impression share and often your sales volume, but does not guarantee a lower ACoS if the core problem is poor keyword relevance or low listing conversion rate. If shoppers who click on your ad are not buying, you need fewer of the wrong clicks, not cheaper ones. Reducing bids on non-converting keywords or pausing them entirely is more effective than applying a blanket bid reduction across a campaign.

How long does it take to lower ACoS on Amazon PPC?

Most ACoS improvement takes four to eight weeks of consistent optimisation to show a sustained change. Immediate improvements, such as pausing high-spend non-converting keywords, can show in the first week's data. Structural changes, such as moving keywords from auto to manual campaigns and optimising bids based on conversion data, typically require four to six weeks before enough new data accumulates to show a reliable trend. Listing improvements that affect conversion rate also take time to be reflected in ACoS as the new listing experiences are measured across a sufficient number of clicks.

Should I pause keywords with a high ACoS or just reduce the bid?

It depends on why the ACoS is high. If a keyword has a high ACoS because the bid is too high relative to its conversion rate, reducing the bid is the right action. If a keyword has a high ACoS because it is generating clicks with very few or no conversions, it is likely a poor match for your product and should be paused or moved to negative. Check the conversion rate of each keyword before deciding: a 0% conversion rate over 20 or more clicks suggests a relevance problem that a lower bid will not solve.

How do I lower ACoS on Amazon?

You lower ACoS on Amazon by either reducing the cost of getting a click or increasing the number of those clicks that convert to sales. In practice that means improving keyword relevance, eliminating wasted spend on non-converting search terms, and making sure your listing converts the traffic your ads are sending to it. ACoS is the result of two variables: your cost per click and your conversion rate. Lower your cost per click without changing conversion rate and ACoS falls. Increase your conversion rate without changing your bids and ACoS falls. Improve both simultaneously and ACoS falls significantly. Most ACoS reduction strategies focus on the spend side, specifically cutting wasted clicks from irrelevant search terms, which is correct but incomplete. A low-relevance keyword costs money because shoppers click and do not buy. But a highly relevant keyword with a poor listing also costs money for the same reason: shoppers click, the listing fails to convince them, and they leave without purchasing. Both problems need addressing, often at the same time. Download your search term report from Amazon's advertising console and filter for search terms that have generated clicks with zero or very few sales over a meaningful period (at least 30 days of data, ideally 60 days). Any term with significant spend and no conversions is likely dragging your ACoS up. Add these as negative exact-match keywords to prevent your ads from showing for them in future. Be systematic rather than reactive. Look for patterns in the non-converting terms: are they too broad (someone searching for a general category rather than your specific product), too distant in intent (a research query rather than a buying query), or a competitor or brand name that is not your own? Each pattern points to a different root cause in your campaign targeting that can be addressed beyond the individual negative keyword. If your keywords are relevant but your conversion rate is low, the problem is your listing rather than your campaign. Shoppers are arriving, deciding not to buy, and leaving. Every click you pay for without a conversion raises ACoS. Fixing the listing reduces ACoS without changing a single bid. The highest-impact listing elements for conversion rate are your main image and your first three images in the image carousel (as these are visible before scrolling on mobile), your title (does it clearly communicate what the product is and for whom), and your bullet points (do they address the specific concerns and use cases of the shopper who found you through that keyword). If you are advertising on a specific keyword and your listing does not visibly address that use case, clicks from that keyword will convert poorly. Auto campaigns are efficient for discovery but inefficient for long-term cost control. They bid broadly and pick up irrelevant traffic alongside converting terms. Once you have identified which search terms convert in your auto campaigns, move those terms into a dedicated manual campaign with exact-match targeting. Exact-match reduces irrelevant impression share and gives you direct control over the bid for each proven term. Within manual campaigns, separate your keywords by performance tier. High-converting, low-ACoS terms warrant higher bids to protect their positions. Mid-performing terms can be held at moderate bids and monitored. Poor-performing terms should be bid down or paused. This structure prevents your best keywords from being averaged out against your worst ones within a single campaign with a single bid setting.

Lower ACoS by targeting more relevant keywords, pausing wasted spend, improving your listing's conversion rate and restructuring your campaigns.