How to Lower Your Amazon ACOS: A Complete Guide for Sellers

If you're advertising on Amazon, ACOS — Advertising Cost of Sale — is the metric that either keeps you up at night or gives you confidence you're spending wisely. A high ACOS means you're spending too much to generate each sale. A well-optimised ACOS means your campaigns are efficient and your margins are protected. This guide covers exactly how to lower it.

What Is ACOS and How Do You Calculate It?

ACOS is expressed as a percentage and calculated with a simple formula:

For example, if you spent $200 on ads and generated $1,000 in ad-attributed sales, your ACOS is 20%. The lower the percentage, the more efficient your advertising spend.

It's important to distinguish ACOS from TACOS (Total Advertising Cost of Sale), which divides ad spend by your total revenue including organic sales. TACOS gives a holistic view of how ads support your overall business, while ACOS specifically measures paid campaign efficiency.

What Is a Good ACOS? Benchmarks by Category

There's no universal "good" ACOS — it depends on your product margins, category, and business goals. That said, here are typical benchmarks:

• Break-even ACOS: Your profit margin percentage. If you make 35% margin, your break-even ACOS is 35%.
• Target ACOS: Below break-even — typically 15–25% for established products.
• Launch ACOS: Can be 40–70%+ when building rank and reviews. Acceptable short-term.
• Home & Kitchen: Average ACOS around 20–28%
• Electronics: Average ACOS around 12–18% (lower margins require tighter efficiency)
• Supplements & Beauty: Average ACOS around 18–30% (high competition, frequent launches)
• Apparel: Average ACOS around 22–35% (high return rates impact profitability)

The key is calculating your break-even ACOS first, then setting a target 5–10 points below it to maintain healthy margins.

10 Proven Strategies to Lower Your Amazon ACOS

1. Fix Your Campaign Structure

Mixing broad, phrase, and exact match keywords in a single campaign is one of the biggest mistakes sellers make. Use separate campaigns for each match type. This gives you granular control over bids, budgets, and performance data. A clean structure lets you see clearly which match types are driving profitable sales and which are burning budget.

2. Master Keyword Match Types

Broad match keywords drive discovery but attract irrelevant traffic. Exact match keywords are efficient but have limited reach. The optimal approach: run broad and phrase match campaigns to discover converting search terms, then move the best performers into exact match campaigns with higher bids and dedicated budgets. This harvesting strategy systematically improves ACOS over time.

3. Implement Aggressive Negative Keywords

Negative keywords are the single fastest way to lower ACOS. Review your Search Term Report weekly and add non-converting terms as negatives. Look for: irrelevant product categories, competitor brand names (unless intentionally targeting), searcher intent mismatches (e.g., "how to" queries if you're selling a physical product), and geographic terms if you don't ship there. Most accounts reduce wasted spend by 20–30% within 30 days of active negative keyword management.

4. Bid Strategically — Don't Set and Forget

Static bids are ACOS killers. Use dynamic bidding (down only for established campaigns, up and down for aggressive growth phases). Increase bids on keywords converting at or below your target ACOS. Decrease bids on keywords spending without converting. A simple rule: if a keyword has spent 2× your average order value without a sale, reduce the bid by 25–30% or pause it.

5. Use Dayparting to Control When Your Ads Run

Not all hours are equal. Pull your hourly performance data from Amazon reports and identify peak conversion windows. For most ecommerce categories, evenings (7pm–10pm) and weekends convert best. Use rules-based bidding or third-party software (Perpetua, Teikametrics, Pacvue) to automatically adjust bids up during high-conversion periods and down during low-conversion hours. Sellers typically see 8–15% ACOS improvement from dayparting alone.

6. Leverage Product Targeting Campaigns

Product targeting allows you to place ads on specific competitor ASINs or your own product pages. Target competitor listings with lower ratings, higher prices, or out-of-stock items — these are conversion opportunities. Also target your own listings to capture upsell and cross-sell traffic. ASIN-level targeting often outperforms keyword campaigns for products with strong visual differentiation.

7. Optimise Your Product Listing

Your listing is where clicks become sales. A high click-through rate (CTR) combined with a low conversion rate is a listing problem, not a campaign problem. Address: main image quality (high-resolution, white background, product fills 85% of frame), title with primary keyword, benefit-driven bullet points, A+ Content (proven to increase conversion rates 3–10%), and review count (products with fewer than 15 reviews have substantially lower conversion rates). Improving your listing conversion rate directly reduces ACOS because every click is now more likely to result in a sale.

8. Allocate Budget Intelligently

Your best-performing campaigns should rarely run out of budget. Audit budget allocation monthly. Move budget away from high-ACOS campaigns toward low-ACOS ones. Set hourly budget caps on campaigns that tend to overspend in off-peak hours. Most sellers find that their top 20% of campaigns drive 60–70% of profitable sales — give these campaigns room to scale.

9. A/B Test Ad Copy in Sponsored Brands

If you're running Sponsored Brand campaigns, test different headlines. Amazon's A/B testing tool lets you run headline experiments directly in Seller Central. Strong headlines that include the main customer benefit — not just the brand name — typically generate 15–25% higher CTR, which ultimately improves conversion efficiency and ACOS.

10. Harvest Search Terms Systematically

Download your Search Term Report every 7–14 days. For every term that has converted at or below your target ACOS, create a dedicated exact match campaign with a slightly higher bid than your broad campaign. This ensures your most profitable terms get maximum visibility and budget. Over 90 days, this process builds a library of proven exact match keywords that form the backbone of a highly efficient account.

Putting It All Together: A 30-Day ACOS Reduction Plan

Week 1: Audit campaign structure. Add all obvious negative keywords. Calculate your break-even and target ACOS.

Week 2: Pull Search Term Reports. Start harvesting winners into exact match campaigns. Pause or reduce bids on keywords spending 2× AOV without converting.

Week 3: Review listing conversion rate. Fix the main image, title, and bullets if CTR is high but conversion is low. Set up dayparting rules.

Week 4: Reallocate budget from worst-performing to best-performing campaigns. Review ACOS trends and document what's working.

Lowering ACOS is an ongoing process, not a one-time fix. The sellers who win on Amazon long-term are the ones who treat campaign optimisation as a weekly discipline, not an occasional task. If you'd rather have experts manage this for you, explore Marketikx's Amazon advertising services or learn more about Amazon DSP advertising to extend your reach beyond Sponsored Ads.