You don’t feel “high ACOS” in a spreadsheet. You feel it when a product that should be scaling is stuck in a loop: spend climbs, sales stay flat, and your margin quietly disappears. The fix is rarely one magic bid change. ACOS comes down when your targeting, bids, and traffic quality start behaving like a system.
This is a practical, operator-level guide on how to reduce acos on amazon without accidentally turning your campaigns off.
ACOS reduction starts with one uncomfortable question
Before you touch bids, decide what you’re actually optimizing for.
If your goal is profit, you need a target ACOS that matches real unit economics, not an arbitrary “20% sounds good.” Work backward from contribution margin after fees, COGS, and fulfillment. Then account for what you’re willing to spend for growth. A new-to-brand SKU may justify a higher ACOS temporarily if it increases organic rank and repeat purchases. An aging SKU with thin margin usually can’t.
This matters because the same “high ACOS” number can mean two totally different problems:
A campaign can be expensive because it’s inefficient (bad queries, wrong placements, bloated bids). Or it can be expensive because it’s doing its job (buying ranking or protecting a category position). If you don’t label which is which, you’ll cut the wrong spend.
Diagnose where the ACOS is coming from (campaigns are not equal)
Start by separating your ad spend into buckets by intent. If you lump everything together, you’ll keep making average decisions that create below-average results.
At minimum, break performance down into branded search, non-branded search, product targeting, and remarketing-style traffic (if you run it). Branded ACOS tends to be lowest but can be wasteful if you’re paying for customers who would have bought anyway. Non-branded is where you earn scale, but it’s also where query quality can destroy efficiency. Product targeting can be amazing when tightly controlled and terrible when it’s just “spray and pray.”
Now look for the pattern, not the outlier. If ACOS is high in one bucket, your fix should match the failure mode.
Fix the fastest leak first: search term waste
If you want the quickest path to lower ACOS, go straight to search term reports and ask: which queries are spending money without proving intent?
Most high-ACOS accounts have one of these issues:
You’re buying “research” queries at “ready-to-buy” bids
Words like “best,” “top,” “review,” “vs,” “alternative,” or broad category terms can convert - but they usually convert at a higher cost and longer time horizon. If your bids are set as if every click is a purchase, you’ll inflate ACOS.
The move is not “pause all broad terms.” The move is to bid them like upper-funnel traffic and force them to earn more budget only after they show conversion.
Your match types are doing different jobs, but you’re paying them the same
Exact, phrase, and broad should not share the same bid logic. Exact is your precision tool. Phrase and broad are your discovery and expansion tools. When discovery match types are funded like exact, you pay too much to learn.
A cleaner system is to keep exact keywords as the primary efficiency driver and run phrase/broad with controlled bids and stricter negative rules. You can still discover winners - you just don’t subsidize endless exploration.
Your negatives are too slow
Every week you delay negative keyword actions is another week you fund irrelevant traffic. And irrelevant traffic doesn’t just burn spend - it pollutes your data and makes automation harder.
Add negatives based on a simple standard: if a query has enough clicks to be “tested” and it’s not converting to your benchmark, stop paying for it. The threshold depends on price point and category, but the discipline is universal.
Bid control: stop paying yesterday’s price for today’s traffic
Bids should not be static. Amazon auction dynamics change hourly. Competitors run out of budget, surge at night, push coupons, and come back with aggressive placement multipliers. If you’re only adjusting bids once or twice a week, you’re constantly reacting late.
To reduce ACOS, you need two layers of bid logic:
First, guardrails that prevent overbidding when conversion rate drops. If your CVR falls because you lost the Buy Box, your listing rating dipped, or your inventory is low, the correct response is to lower bids, not “spend through it.”
Second, escalation rules for proven winners. A keyword that converts profitably should be allowed to scale. Most teams do the opposite: they keep winners underfunded because they’re afraid of ACOS drift, then keep funding losers because “maybe it’ll work.”
The clean approach is to increase bids only where you have repeatable conversion and to cut bids quickly where you don’t. That’s how you lower ACOS while keeping sales velocity.
Placement optimization: ACOS is often a “where” problem
A lot of accounts run high ACOS because they’re paying premium CPCs for premium placements that aren’t actually premium for their product.
Top of Search can be profitable when your listing is already strong: sharp main image, clear value prop, competitive price, and reviews that hold up. If your conversion rate is mediocre, Top of Search amplifies the problem because clicks are expensive.
Product pages are different. They can be cheaper and can convert well for complementary items or competitive conquesting - but only if you’re deliberate about which ASINs you target.
Run placement reporting like you would run keyword reporting. If a placement consistently shows worse ACOS at similar or lower conversion, dial it down. If a placement is printing profit, you can afford to push it.
Be careful with blanket placement multipliers. A 50% Top of Search boost across every campaign is a fast way to raise ACOS across every campaign.
Budget pacing: don’t let Amazon choose your worst hours
Budgets aren’t just a cap. They’re a steering wheel.
If your campaign runs out of budget early, Amazon prioritizes where your spend goes during the hours you are live - and those hours are not always your most efficient.
Day-parting is one of the most underused levers for ACOS control because it feels “advanced,” but the logic is simple: if conversion rate drops at certain times, your ACOS will spike. If you keep spending through those windows, you’re buying worse traffic at the same price.
Start by identifying when ACOS inflates. Then reduce bids or pause during those windows, especially for discovery campaigns. Keep your best-performing hours protected with sufficient budget so you’re not offline when buyers are actually converting.
Targeting strategy: separate discovery from performance
Campaign structure is not an aesthetic choice. It determines whether you can control ACOS without choking growth.
A high-functioning structure does one thing well: it keeps your “learning spend” from contaminating your “profit spend.”
Discovery campaigns (auto, broad, phrase, category targeting) exist to find winners. They should have tighter budgets, lower bids, and faster negative harvesting.
Performance campaigns (exact keywords and proven product targets) exist to scale. They should get the budget, the placement advantages that actually work, and the bid support to stay competitive.
When everything is mixed together, you end up with a campaign that is half exploration and half exploitation. That’s where ACOS goes to die, because you can’t optimize one behavior without hurting the other.
Listing and offer reality: PPC can’t outbid a weak conversion rate
If you’ve tightened targeting, cleaned negatives, and controlled placements, but ACOS is still high, stop blaming PPC.
Your ads can only be as efficient as your conversion rate allows. Common listing-side ACOS killers include weak main image contrast, unclear differentiation in the first 2 lines of the title, thin reviews relative to the category, and price gaps that buyers can’t justify.
Also watch the Buy Box and inventory. Losing the Buy Box turns paid traffic into donations. Low inventory can throttle conversion and spike CPC-to-sale ratios.
Sometimes the best ACOS move is a listing move: tighten the hero image, improve A+ clarity, adjust price testing, or run a coupon that lifts conversion enough to offset the cost.
The “it depends” part: when higher ACOS is the correct play
There are scenarios where lowering ACOS is not the goal - at least not immediately.
If you’re launching, you may choose to run above target ACOS to generate sales history, keyword rank, and reviews. If you’re defending a core keyword that drives organic halo, you might accept a higher paid ACOS because total blended ACOS stays healthy. If you’re clearing inventory, you might run aggressive spend to move units quickly.
The key is to decide intentionally. High ACOS that you chose is a strategy. High ACOS that surprises you is a leak.
How teams make this sustainable (without living in spreadsheets)
Most sellers don’t fail at ACOS because they don’t know the levers. They fail because they can’t pull them often enough.
Reducing ACOS consistently requires a repeatable loop: harvest search terms, negate waste, promote winners to exact, adjust bids based on fresh performance, and control budgets and placements by what’s happening right now, not last week.
If you want that loop running without spending 20 hours a week babysitting the console, this is exactly what platforms like AdFixer are built for: always-on bid updates, keyword discovery and negatives, day-parting, placement controls, and goal-based optimization toward a target ACOS or ROAS.
The closing thought to keep on your desk is simple: ACOS doesn’t drop because you “optimize more.” It drops when you stop paying for uncertainty and start funding proof.
