Amazon PPC: How to Cut ACoS Without Losing Sales

Most Amazon sellers who say “PPC doesn’t work for us” don’t have an advertising problem. They have a structure problem. Campaigns are built once, left on autopilot, and judged on a single number that hides where the money actually goes. This guide walks through how we audit and rebuild PPC accounts so ACoS comes down without sales falling with it.

Start with the right numbers: ACoS, TACoS and break-even ACoS

ACoS (advertising cost of sale) is ad spend divided by ad sales. It tells you how efficient your ads are, but not whether they are profitable.

Break-even ACoS is your profit margin before advertising. If a product sells for $30 and you keep $9 after product cost, FBA fees and referral fees, your break-even ACoS is 30%. Anything below that makes money on the ad sale itself; anything above loses money on it.

TACoS (total advertising cost of sale) is ad spend divided by total sales, organic included. It is the number that shows whether ads are building the brand. A falling TACoS while total sales grow means ads are lifting organic rank. A rising TACoS means you are buying sales you would not keep without ads.

Set a target for each product: a launch product can run above break-even for a few weeks to earn rank, while a mature product should sit well below it.

The 5 leaks we find in almost every account

1. No negative keywords. Auto and broad campaigns keep paying for searches that never convert. A weekly search term review with negatives added is the fastest ACoS win in most accounts.
2. Everything in one campaign. When branded, generic and competitor keywords share a budget, the cheap branded clicks hide the expensive generic ones. Split them so each can have its own bids and targets.
3. Bids that never change. A keyword converting at 15% and one converting at 3% should not have the same bid. Adjust bids on real conversion data at least weekly.
4. Advertising a weak listing. Ads only bring traffic. If the main image, price, rating or bullets lose against the products next to you, more spend just buys more bounces. Fix conversion first.
5. Ignoring placements. Top-of-search often converts far better than product pages. Use placement adjustments based on the numbers, not on habit.

A simple campaign structure that scales

• Research: one auto campaign and one broad campaign with modest bids, used to discover search terms.
• Performance: exact-match campaigns holding the keywords that have proven they convert, with higher bids and their own budget.
• Brand defense: your own brand terms, so competitors cannot buy your customers cheaply.
• Competitor targeting: product targeting on competitor ASINs with weaker ratings, higher prices or fewer images than yours.

Every week, move converting search terms from research into exact match, and add them as negatives in the research campaigns so you do not bid against yourself.

A 12-week plan for a new or relaunched product

• Weeks 1–2 (Launch): exact match on the main keywords plus an auto campaign. Accept a higher ACoS to collect data and first sales.
• Weeks 3–8 (Growth): harvest search terms, add negatives, raise bids on winners and cut keywords that spend without converting.
• Weeks 9–12 (Profit): push the profitable terms, trim the rest, and bring ACoS under your target while watching TACoS.

What results look like

Across the case studies published on our site, managed accounts average a 23% ACoS against an industry average of 30% and above. The point is not a magic number. It is a process: clean structure, weekly search term work, and a listing that converts the traffic you pay for.

Want us to look at your account?

Our free Brand Doctor Pro audit scores your listing, keywords and competitors and puts a dollar range on what each gap is costing you. Request your free audit and we will walk you through the findings on a 30-minute call.