Case Study · Automotive

A dormant account to $3.5M a year in twelve months

A performance auto parts brand had been on Amazon since 2020 and treating it as a secondary channel the whole time. Advertising had been dialled to near zero after an expensive, unproductive push in 2022. We took the account on in mid-2025. Twelve months later it turns over $3.49M, with 57% of that arriving organically and total ad spend at 10.5% of revenue.

$3,489,795

Ordered product sales

trailing twelve months

15,013

Units ordered

around $232 average selling price

10.5%

TACoS

$365,763 spend against all revenue

57%

Organic and non-attributed sales

$1.99M of the $3.49M

4.09x

Return on ad spend

24.44% ACoS

$1.50M

Ad-attributed sales

on $365,763 in spend

How to read the numbers. Sales and units come from the Seller Central business report for the trailing twelve months. Advertising figures come from the Amazon Ads console for 29 September 2025 to 29 September 2026. That window sits entirely inside our engagement, which began in mid-2025. The console also reports lifetime figures going back to 2020, and those are deliberately not used here: they include five years of prior management and are not ours to claim. We do not guarantee outcomes. We show our work.

Read This First

Two numbers here look bad. Both are correct.

A 1.2% conversion rate and a 24.44% ACoS would be alarming on most accounts. On this catalog they are the right numbers, and understanding why is most of the strategy.

The 1.2% conversion rate is the category working as intended

These are fitment-dependent parts: custom exhaust systems, heavy-duty suspension components, model-specific engine internals. At roughly $232 a unit, nobody buys on impulse. Shoppers open the listing to cross-reference compatibility tables, engine variants and year, make and model widgets, often several times across several days, before committing to a mechanical purchase that has to physically fit their vehicle.

Why it worked: Fitment research is a feature of the buying process, not a failure of the listing. Optimising to lift this number would mean attracting shoppers who cannot use the part, which shows up later as returns.

The 24.44% ACoS is affordable because of what sits behind it

High-ticket performance parts carry deep manufacturer and distributor margins, frequently 50% to 60% and above, so a 24% ACoS still leaves real contribution per order. Lifetime value compounds on top: garages, mechanics and enthusiasts who trust a supplier come back for the next build. The ACoS number in isolation says very little.

Why it worked: TACoS is 10.5%. Ad spend is a tenth of total revenue while advertising is credited with 43% of sales, because the other 57% comes in organically. That is a self-sustaining account, not an ad-dependent one.

The metric that actually matters here is TACoS. ACoS only measures advertising against the sales advertising was credited with. TACoS measures it against everything the account sold. At 10.5%, this account is spending a tenth of its revenue on ads to sustain a catalog where most sales now arrive without paying for the click.

Background

What we inherited

A five-year dormancy. The account had existed since 2020 but was under-managed throughout, treated as a secondary channel behind the brand’s other routes to market. Volume stayed low because nothing was driving it.

An expensive lesson already learned. There had been a significant advertising push in 2022 that generated substantial cost with almost no conversion traction. After that, spend was dialled back to near zero and left there. The account was not failing so much as parked.

Our engagement. We took the account on around June and July 2025, with scaling beginning in July and sustained through September 2026.

Strategy

Three decisions that restarted the account

Fix the fitment data before spending a dollar on ads

We overhauled the listing backends to map correctly to Amazon’s Part Finder and Confirmed Fit systems. That puts the year, make and model check directly on the listing, so the shopper gets a definitive answer instead of trying to interpret a compatibility table themselves.

Why it worked: Fitment friction is the single largest source of both lost sales and returns in this category. A buyer who cannot confirm the part fits does not buy, and a buyer who guesses wrong sends it back.

Target the vehicle, not the part

We moved spend away from hyper-generic terms such as “performance exhaust” and onto year-and-model long tail: the shopper searching “2018 silverado 5.3 cat back exhaust” already knows what they need. Ad dollars only bought clicks that matched inventory actually in stock.

Why it worked: A click from someone searching their exact vehicle and part is worth many times a click from someone searching the generic category, and costs less. On a fitment catalog, specificity is the whole game.

Price for the trade, not just the enthusiast

We configured tiered volume discounts aimed at independent repair shops and local mechanics buying commercial fleet replacements. The enthusiast buying one part for one truck is a good customer. The shop buying twelve is a better one.

Why it worked: Repair shops and fleet buyers order repeatedly and in volume, which lifts both order value and lifetime value on a catalog where a single customer may fit out many vehicles.

Results

Where the sales come from

Organic and non-attributed$1.99M (57%)

Ad-attributed$1.50M (43%)

Ad spend$365,763 (10.5%)

Trailing twelve months. Advertising is credited with 43% of sales while costing 10.5% of revenue, and the majority of the catalog's sales now arrive without a paid click.

Trailing twelve months	Value
Ordered product sales	$3,489,795
Units ordered	15,013
Average selling price	approx. $232
Conversion rate	1.2%
Ad-attributed sales	$1,496,579
Ad spend	$365,763
ACoS	24.44%
TACoS	10.5%
ROAS	4.09x

Sales and units from the Seller Central business report; advertising figures from the Amazon Ads console, 29 Sep 2025 to 29 Sep 2026.

Honesty

What did not go to plan

Amazon's fitment catalog kept moving
Changes to Amazon's automotive fitment requirements periodically broke variations or wiped specific vehicle compatibility from listings. Each time, conversion dropped until the data strings were re-mapped. On a fitment catalog this is not a one-time setup task, it is maintenance, and we treat it that way now.
Stockouts on long lead-time parts
These parts take a long time to manufacture, so demand spikes we created outran supply on hero units. We had to suppress ad spend during those windows to avoid driving traffic to unavailable inventory and losing organic rank. Better demand forecasting into the manufacturing cycle is the open problem on this account.

If your account looks like this one

This playbook transfers to fitment or compatibility-driven catalogs, to high-ticket considered purchases where a low conversion rate is normal rather than broken, to accounts that have been parked after an expensive advertising experiment went badly, and to any catalog with a trade buyer sitting alongside the consumer one. It starts with the product data, not the campaigns.

We do not guarantee sales or rankings, and we will tell you when the data says no. Send us your last 90 days of Business Report and advertising exports and we will return a written audit with a plan of action, risks included.

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