Most sellers are making at least one of these errors right now — silently burning through margin they don't even know they're losing.
Amazon PPC is one of the most powerful tools in a seller's arsenal — and one of the easiest ways to bleed money unnecessarily. Most campaigns we audit have at least three of the five mistakes below. Each one costs a few hundred to several thousand euros per month depending on campaign spend. They're not hard to fix. You just need to know what to look for.
Broad match is Amazon's default keyword match type, and it casts the widest net. That's the problem. A broad keyword like "water bottle" can show your ad for "water bottle for dogs," "water bottle insulated," and "sports water bottle large." You're paying for every variation — even when it has nothing to do with what you're selling.
Without negative keywords, your campaign collects irrelevant search queries like a sponge. Every irrelevant click is money you pay but never recover, and it tanks your ACOS in ways that don't show up on the surface unless you dig into search term reports.
We've seen campaigns where 30–40% of ad spend was going to search terms that had zero conversion — pure waste, hidden behind broad match sprawl.
Mercanto scans your search term reports weekly, identifies irrelevant queries by category and context, and adds them as negative exact or phrase matches automatically. It also flags high-spend keywords that are too broad and suggests tighter match alternatives. You get the reach of broad match without the collateral damage.
Amazon lets you bid differently for three placements: top of search, product pages, and the rest of search. Most sellers use a single bid across all placements. But the math doesn't work — top-of-search placements typically convert 2–4x better than product pages, and your cost-per-click should reflect that.
When you don't adjust placement bids, you're either overpaying on product pages (your CPC is too high for a lower-converting placement) or underbidding on top-of-search and missing the best conversions for your product.
With a 30% placement adjustment, a seller spending €3,000/month can often maintain the same ROAS while increasing total conversions — or keep conversions flat while reducing spend by 15–25%.
Mercanto analyzes your historical placement performance, identifies the optimal bid modifier for each campaign based on actual ROAS by placement, and adjusts weekly. Campaigns that overperform on product pages get a modest bid boost there while top-of-search bids are kept competitive for high-converting terms.
Auto campaigns are a great discovery tool. You upload your keywords, Amazon finds relevant searches, and you get data. But there's a critical error sellers make: they keep auto campaigns running indefinitely without moving winning keywords into manual campaigns.
Auto campaign bids are typically 2–3x higher than manual campaign bids for the same keyword position. Why? Auto campaigns compete against all relevant keywords automatically, which drives up the auction price. Once you've identified a high-performing keyword from your auto campaign, you should move it to a manual campaign with a targeted bid — cheaper clicks, same or better placement.
Leaving all your keywords in auto campaigns is like paying retail for everything when you have wholesale access. It's completely optional waste.
Mercanto identifies keywords from auto campaigns that have reached statistical significance (enough clicks and conversions to trust the data), grades them by ACOS efficiency, and recommends which to migrate to manual campaigns. You keep the winning terms at lower CPCs while auto campaigns continue hunting for new opportunities.
Amazon's search term report is the most valuable data source in your advertising account — and most sellers never open it. It shows you exactly which queries triggered your ads, how much you spent, and what you got back. Without this data, you're advertising blind.
The most common patterns we see: brands bidding on their own product name (wasting money competing with themselves), irrelevant long-tail queries driving spend with zero conversions, competitor ASIN targeting that looks like it's working but is actually draining budget with high CPA, and product variants (size/color) being grouped when they should be separated.
Search term reports need to be reviewed at minimum every 7 days to keep campaigns clean. A campaign that goes 30 days without a review can accumulate hundreds of wasted search terms and thousands in unnecessary spend.
Mercanto pulls search term reports daily and runs a multi-factor filter: conversion rate, ACOS by search term, spend efficiency, and brand vs. non-brand split. It surfaces the top 20 highest-waste terms each week with recommended actions. Instead of spending hours in Amazon's UI, you get a prioritized action list — add negative, move to manual, adjust bid, or pause.
Bids that worked in January may be actively losing money in March. Keyword performance changes with seasonality, competitor activity, organic rank shifts, and listing changes. A static bid is a snapshot taken once and treated as a constant — it's not.
The most common consequence: a keyword that converted at a 20% ACOS in January is now running at 35% ACOS by April because a competitor lowered their bid and your ad position dropped to a lower-traffic spot, or your organic rank improved and you're now paying for conversions you'd have gotten organically anyway.
Most sellers don't discover this until they're 60 days deep and have blown through their quarterly advertising budget on thin margins.
Mercanto monitors keyword-level ACOS trends and triggers bid adjustments when a keyword's ACOS drifts more than 2 points from target. It also factors in dayparting (bid adjustments by time of day), device performance, and seasonal signals to predict the right bid before drift becomes a problem. Bids are updated weekly, with full audit trails so you always know why a change was made.
These aren't complicated errors. They're all symptoms of the same underlying problem: Amazon PPC requires continuous attention, and most sellers don't have the time to give it.
Perpetua and Pacvue automate some of this — but at €695–1,000+/month, they're built for enterprise sellers. Mercanto does the same optimization work at a fraction of the cost, with explainable recommendations so you always know why a bid was changed or a keyword was paused.
If you've run Amazon PPC for more than three months and haven't reviewed your search term report this week, that's where to start. One honest audit can reveal waste you didn't know existed.
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