Amazon Ads mistakes rarely show up as a single disaster. They appear as a slowly rising ACoS, budgets that run out by midday, search terms that collect clicks for months without a sale and branded campaigns that make the account look healthier than it is. Most of the waste comes from setup and process problems, such as missing negative keywords, poor structure and weak product pages, rather than from bids being slightly too high.
Running ads on listings that are not ready
Ads send traffic; the listing converts it. If the main image is weak, the title is unclear, there are few reviews or the price is out of line with competitors, every click costs more than it should. Ads cannot fix a listing that shoppers reject.
Before scaling ads, check the listing. Look at unit session percentage (conversion rate) in Business Reports > Detail Page Sales and Traffic. Compare your main image, price, review count and rating with the top three competitors for your main keyword. Fix the most obvious gap first.
Why does skipping negative keywords cost so much?
Automatic, broad and phrase campaigns match your ads to many search terms, and some will never convert. A kettle brand might find its ads showing for “kettle descaler”, “kettle replacement lid” or “kettle bell”, none of which lead to a kettle sale.
Without negative keywords, those clicks repeat every day. Download the Search Term report regularly and add irrelevant terms as negative exact or negative phrase. Also add negative product targets for ASINs that clearly do not convert. Small daily leaks add up to a large share of spend over a quarter.
Should brand and non-brand keywords share a campaign?
Shoppers who search for your brand name already want your product, so branded keywords usually show very low ACoS. When they sit in the same campaign as generic keywords, the average looks good while non-brand terms may be losing money.
No. Keep branded keywords and your own ASINs in separate campaigns. Judge non-brand campaigns on their own ACoS and new-to-brand metrics, and treat brand campaigns as defence against competitors bidding on your name.
Using the wrong ACoS target
A single ACoS target for the whole account ignores differences in margin and goals. A product with a 50 percent margin can afford a much higher ACoS than one with 20 percent. A new product building reviews may need to accept a loss on ads for a period.
Calculate break-even ACoS per product from its margin. Set targets by product and stage, and track TACoS (ad spend divided by total sales) to see whether ads help organic sales grow. If TACoS keeps rising while organic sales stay flat, ads are replacing organic sales rather than adding to them.
Letting campaigns compete with each other
When the same keyword sits in several campaigns, or a converting search term remains in the automatic campaign after being added as exact match, your own campaigns bid against each other. Reporting becomes confusing and costs rise.
Fix it with a harvesting routine: when a search term moves to an exact match campaign, add it as negative exact in the discovery campaign it came from. Keep a simple sheet of which keyword lives in which campaign.
Forgetting about Sponsored Display and product targeting settings
Sponsored Display campaigns created with default settings can spend on broad audiences and placements that rarely convert. Check the targeting type, audience lookback window and bid optimisation choice (page visits, conversions or reach) before launch. Product targeting campaigns need the same care: targeting a whole category instead of specific ASINs often spreads budget across products that are not real alternatives to yours.
Review these campaigns separately from Sponsored Products, with their own targets. Their role is often retargeting and defence, so judge them on new-to-brand orders and return visits as well as ACoS.
Is changing bids every day a mistake?
Usually, yes. Amazon attribution reports sales for Sponsored Products within a seven-day window, and data for recent days keeps updating. Changing bids daily based on one or two days of data means reacting to noise and to sales that have not been attributed yet.
Set a rhythm instead. Review weekly, change bids only on keywords with enough clicks, and avoid adjusting the same keyword twice in a week. Keep a change log so you can see what each adjustment did.
More mistakes worth checking
Several smaller issues also waste budget in many accounts:
- Budgets that run out early. Check the “out of budget” indicator and move budget from weak campaigns to strong ones that miss sales.
- Ignoring placement data. Top of search may convert much better than product pages; adjust placement bids accordingly.
- Advertising out-of-stock or low-stock products, which wastes clicks and can hurt ranking.
- Advertising every variation equally, when one size or colour converts far better.
- Using “up and down” dynamic bidding in discovery campaigns, which raises bids on unproven terms.
- Never testing Sponsored Brands video, which can perform well for products that need demonstration.
- Ignoring the Targeting report’s impression share, which shows where you are missing visibility on proven terms.
A monthly account audit checklist
Run this once a month to catch the mistakes above before they grow:
- Compare conversion rate and price against the main competitors for top products.
- Review the last 30 days of search terms; add negatives and harvest winners.
- Check that brand and non-brand campaigns are separate.
- Compare ACoS by product with each product’s break-even ACoS.
- Look for keywords that appear in more than one campaign.
- Review out-of-budget campaigns and placement reports.
- Confirm inventory levels for advertised products.
- Check TACoS trend over the last three months.
Building a process instead of fixing mistakes one by one
Most of the mistakes above come back if nobody owns the account routine. Assign one person to the weekly review, give them a written checklist and agree on the targets per product in advance. When results change, that person should be able to point to the search term report, the change log or a listing issue, rather than guessing.
A shared folder with the latest reports, the target sheet and the change log also makes it easier to bring in help, whether a new team member or an outside specialist, without losing what has already been learned.
Where to start this week
Pick the campaign with the highest spend and download its last 60 days of search terms. Sort by spend and highlight every term with meaningful clicks and no orders. Add those as negatives, then check whether any branded terms are mixed into the campaign and move them to their own. These two fixes alone often reduce wasted spend noticeably, and they set up a cleaner account for every optimisation that follows.
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