When ACOS creeps up, most sellers react the same way: cut budgets, lower bids, wait it out. That usually just slows the account down without fixing anything. In almost every account we audit, the real cause is structural — a handful of setup mistakes compounding every day the campaigns run. Here are the seven we find most often, and how we fix each one.
1. Your brand name has no fortress around it
If you’re not bidding on your own brand terms, competitors are — and they’re winning some of your highest-intent traffic for a fraction of what you’d pay elsewhere. A branded defensive campaign is usually the cheapest traffic on the account, with the best conversion rate. Skipping it doesn’t save money; it hands cheap sales to someone else's ad spend.
2. Auto and manual campaigns are fighting each other
Auto campaigns are a research tool, not a scaling tool. When auto and manual campaigns target the same keywords with no exclusions between them, you end up bidding against yourself — two of your own campaigns competing for the same auction, inflating your own cost per click. Auto campaigns should mine search terms; manual campaigns should own the ones that convert, with negatives keeping the two out of each other’s way.
3. No negative keyword discipline
Every account bleeds spend on search terms that will never convert — wrong category, wrong use case, wrong price point. Without a weekly pass on the search term report, that leak never gets capped. It's the single most under-used lever in Sponsored Ads, because it's tedious rather than difficult.
4. Budgets are flat instead of following performance
A campaign that converts well at 2pm on a Tuesday and a campaign that never converts get the same daily budget in most accounts — because nobody's watching closely enough to move it. Budget should follow what's returning, day to day, not sit on a schedule set once a month.
5. Optimising for ACOS instead of profit
ACOS is a ratio, not a number that pays your bills. A campaign at 40% ACOS on a high-margin hero SKU can be more profitable than one at 15% ACOS on a thin-margin accessory. Chasing a single ACOS target across every campaign means underspending on the products that deserve more and overspending on the ones that don't.
The fastest way to catch most of this is a structured weekly review. On a new account, we run through the same checklist every time:
- Search term report — harvest converting terms, add negatives on wasted spend.
- Placement report — check top-of-search vs. product page performance separately.
- Bid vs. conversion rate — raise bids on keywords converting above account average, cut the rest.
- Budget utilisation — flag any campaign hitting its daily cap before midday.
- Dayparting — shift spend toward the hours that actually convert for your category.
6. Sponsored Brands and Display are an afterthought
Most accounts run Sponsored Products and stop there. Sponsored Brands headline ads defend the top of search results from competitors, and Sponsored Display retargets shoppers who viewed your listing but didn't buy — often the cheapest conversions on the whole account. Leaving both off the table means paying more for less coverage.
7. The listing isn't ready for the traffic
No bid strategy fixes a listing that doesn't convert. If the images, title, and bullet points aren't answering a buyer's actual questions, PPC just becomes an expensive way to prove the listing doesn't work. Listing and A+ content optimisation should always come before — or alongside — scaling ad spend, not after.
None of these fixes require a bigger budget. They require someone checking the account often enough to catch the leak before it compounds — which is exactly what continuous account management is for.
If your ACOS has been climbing and you can't point to why, an audit usually finds three or four of these running at once. See how our Amazon brand and PPC management works →