eBay's Cassini search engine decides which listings show up in the first three rows of results, and keywords are the single biggest lever a seller can pull. Titles, item specifics, categories, and description copy all feed Cassini's relevance score. Get the keywords right and a listing earns impressions on day one. Get them wrong and the listing sits buried under three million competing SKUs.
This guide walks through the exact workflow we recommend to Ecomli sellers — from pulling keyword data out of eBay's own search, to placing keywords where Cassini actually reads them, to refreshing underperforming titles every 30 days. Every tactic is built around the question eBay shoppers answer when they type a query: what am I looking for, and how do I describe it?
Why Keywords Drive eBay Rankings More Than Any Other Factor
Cassini ranks listings on a blend of relevance, seller performance, and listing quality. Relevance is where keywords live. When a buyer types "vintage carhartt jacket XL", Cassini pulls every listing that matches those tokens in the title and item specifics, then orders them by recent sell-through, click-through rate, and watchlist activity.
Three practical consequences fall out of that ranking logic:
- A missing token means zero impressions. If your title says "Carhartt Work Jacket Brown Size XL" but the buyer types "Carhartt Detroit Jacket", Cassini won't connect them. One missing model name hides the listing.
- Item specifics are not optional. eBay uses item specifics for filtered navigation. A buyer who ticks "Brand: Carhartt" filters out everything without that specific set. Listings without a brand value vanish from filtered searches.
- Keyword density doesn't help. Stuffing the same term five times in a description is ignored by Cassini and flagged by buyers as spam. Variation and precision beat repetition.
The rest of this guide is about building a keyword list that covers every relevant query, then placing those keywords where Cassini reads them.
How to Research Keywords for eBay Listings
eBay gives sellers three free keyword sources. Each tells a slightly different story, so the research workflow pulls data from all three, then deduplicates.
1. eBay autocomplete (Suggest) for buyer language
Start on eBay.com, type the root term for your product, and record every autocomplete suggestion. These are real buyer queries ordered by recent search volume. For "carhartt jacket" you'd typically see "carhartt jacket men's", "carhartt jacket women's", "carhartt jacket xl", "carhartt jacket detroit", "carhartt jacket j130". Those modifiers — size, gender, model number, colorway — are the exact tokens you need in the title.
Run autocomplete in incognito to strip out your personalized history. Repeat with the root term in plural ("carhartt jackets") and with modifiers you already know are popular ("vintage carhartt jacket"). Ten minutes of this usually produces 25-40 candidate phrases.
2. Sold listings filter for proven buyer intent
On any search results page, tick the "Sold Items" filter in the left rail. This shows completed sales for your query. Scan the first 50 listings and harvest their titles into a document. You're looking for patterns: which model numbers appear most often, which colorways, which condition terms ("new with tags", "NWT", "pre-owned"). The titles that appear in sold listings are the titles buyers actually click and convert on.
This step is the cheat code for listing optimization. You're not guessing what shoppers want — you're reading back the titles that have already turned into money.
3. Terapeak Product Research for 12-month trend data
Every eBay Store subscriber gets free access to Terapeak Product Research. Type your keyword, set the date range to "Last 365 days", and Terapeak returns average sold price, sell-through rate, total listings, and format breakdown (auction vs fixed price). The Keyword report also surfaces top-performing search terms that feed Cassini for that category.
Two numbers to watch: sell-through rate (how many listings actually sold) and average sold price (what buyers paid). A keyword with 80% sell-through and a $45 average sold price is a better target than a keyword with 20% sell-through at $90 — even if the second one sounds more profitable on paper.
4. External tools for volume and difficulty context
Tools like Keyword Tool Dominator, Title Builder, and 3Dsellers pull eBay autocomplete data at scale. Free tiers usually cap at 5-10 searches per day but are enough for most small stores. Ahrefs Keywords Explorer (paid) is useful if you want monthly search volume for the equivalent Google query, which helps when you're deciding whether to invest in a matching blog post or external content piece.
Stitch these four sources together and you'll usually end up with a keyword list of 40-80 candidate terms for a single product. The next question is where to put them.
Where to Place Keywords Inside an eBay Listing
Cassini reads keywords from six specific fields. Ranked by weight:
- Title (80 characters, highest weight)
- Item specifics (structured fields — brand, model, size, color, material, MPN)
- Category (choosing the wrong category hides the listing from filtered browsing)
- Subtitle (paid field, $1.50+, visible but lower weight for ranking)
- Description (indexed but heavily deprioritized since 2018)
- Image alt text and SEO fields (store-level, modest impact)
Building an 80-character title that Cassini loves
Order matters. eBay's own testing shows titles that front-load brand and model outperform titles that start with adjectives. The template we use for Ecomli stores follows this structure:
[Brand] [Model/MPN] [Primary Keyword] [Key Attribute 1] [Key Attribute 2] [Condition]
Example: Carhartt J130 Detroit Jacket Brown Men's XL Duck Canvas Lined Pre-Owned
Every token earns its place. Carhartt and J130 cover buyers searching by brand or model. "Detroit Jacket" covers the popular descriptive search. "Brown" is the colorway. "Men's XL" covers size and gender filters. "Duck Canvas Lined" picks up material filters. "Pre-Owned" matches condition searches. Seventy-eight characters, zero wasted space, no filler words like "nice", "rare", or "beautiful" — those don't get searched.
Item specifics: the field sellers skip most often
This is where DIY sellers lose the most impressions. Cassini treats each item specific as a filterable facet. A buyer who filters "Material: Cotton" in the clothing category will never see your listing if the Material field is blank. Fill every relevant specific — eBay flags the required ones, but the optional fields are where you out-rank competitors who skipped them.
A rule of thumb: if eBay offers a field, fill it. Twenty-five item specifics is not too many for a mid-range category like clothing or electronics.
Subtitle and description — where to be more human
The subtitle costs $1.50 and doesn't feed Cassini's ranking for headline search, but it does appear in SERP snippets and helps with click-through rate. Use it for a single benefit line the title couldn't fit: "Zero-defect, ships within 24 hours from US warehouse."
The description's keyword impact is minor but non-zero. Write the first 160 characters as if they were a meta description — they're what shows in Google's external indexing of eBay listings. After that, focus the copy on converting clicks into purchases: sizing notes, condition details, shipping windows, returns. Cassini gives you impressions; the description closes the sale.
How to Add Keywords to Existing eBay Listings
Most sellers ship listings once and never revisit them. That's money left on the table. eBay rewards listings that get edited and re-optimised with a temporary "new listing" visibility boost. Here's the 10-minute workflow for revising a live listing:
- Open the listing from Seller Hub, click Edit listing.
- In the title field, audit every token. Remove filler words ("gorgeous", "must-see"). Add any model numbers, colorways, or size modifiers you missed on the first pass.
- Scroll to Item specifics. Fill every field eBay suggests. If eBay offers a pre-filled value that matches your product, accept it — those pre-filled values feed Cassini's structured data.
- Rewrite the first line of the description to surface the primary keyword naturally.
- Save. eBay's "new listing" boost typically kicks in within 24 hours.
For sellers running more than 50 live listings, doing this by hand is not realistic. Ecomli's AI title optimizer scans every listing in your store, benchmarks it against top-ranked Cassini results for the same category, and suggests keyword additions and item-specific fills in bulk. What takes ten minutes per listing by hand takes about 40 seconds per listing inside the dashboard.
The 30-Day Keyword Refresh Cycle
Shopper language changes. A model that was "Carhartt Detroit Jacket" in 2024 might be "Carhartt J130 Legacy" in 2026 once the J130 SKU codes take off. Keywords that converted 90 days ago may be losing to newer modifiers today.
Set a calendar reminder for every 30 days and run this three-step refresh across your top 20 revenue-generating listings:
- Re-run autocomplete for the root term. Note any new modifiers.
- Re-scan sold listings for the last 30 days only. Look for new patterns in the titles that are actually selling.
- Check your own impressions in Seller Hub under Performance → Listings. Any listing with impressions declining 20%+ month-over-month is probably missing a keyword that shifted in buyer language.
Inside Ecomli, this refresh cycle runs automatically. The dashboard flags listings where impressions dropped more than 20% against the category average and queues keyword-refresh suggestions. Sellers approve or reject in bulk — the same way a Slack notification queue works.
Common Keyword Mistakes That Kill eBay Rankings
Even experienced sellers trip on these. We've seen every one of them in Ecomli customer stores.
1. Using ALL CAPS in titles
Cassini doesn't rank CAPS higher, and buyers read CAPS as spam. The only exception is actual acronyms (HDMI, USB-C, MPN numbers).
2. Stuffing the same keyword in five places
"Carhartt jacket Carhartt work jacket Carhartt Detroit" doesn't rank higher — it signals low quality and can lead to search suppression. Use the keyword once in the title, once in the description, once in item specifics. Let variants cover the rest.
3. Writing for Google instead of eBay
eBay is not Google. Buyer queries are shorter and more specific. A 60-word SEO intro paragraph doesn't help on eBay — it pushes important copy below the fold on mobile. Write titles and descriptions for the eBay app first; Google discovery is a bonus.
4. Ignoring categories
Listing a pair of sneakers in Clothing, Shoes & Accessories > Men's Shoes is correct. Listing them in Clothing, Shoes & Accessories > Unisex Adult Shoes because you thought it was broader is an impression killer. Wrong category = filtered out of the searches that matter most.
5. Leaving condition blank
Condition is a filter. Buyers searching "used" won't see a listing where condition is unset. Always fill it, even for new-with-tags items.
How Ecomli Automates Keyword Optimization
Manually running autocomplete and Terapeak on every product is fine when you have 20 SKUs. Past 200, it stops scaling. Ecomli's AI listing engine takes the same research workflow described above and runs it on every product in your supplier feed, generating Cassini-optimized titles, item specifics, and descriptions before the listing ever goes live.
Three capabilities worth calling out:
- Title Builder: Pulls eBay autocomplete and sold-listing data in real time, picks the best 80-character combination, and scores the title against the top 10 ranking competitors for the same category.
- Item Specifics Auto-Fill: Maps supplier product attributes (brand, material, size, color) into eBay's structured fields automatically, including pre-filled product identifiers when eBay recognizes the UPC or MPN.
- Impressions Monitor: Tracks every live listing's impression trend and flags the ones dropping behind the category average so you can refresh before the listing loses ranking momentum.
If you're already running our AliExpress to eBay workflow or using the supplier vetting framework, keyword optimization is the third leg of the stool — and the one with the fastest payback because it affects listings you've already published.
Frequently Asked Questions
How many keywords should an eBay title have?
As many as fit inside 80 characters without forcing filler. Most strong titles pack 6-10 meaningful tokens: brand, model, primary keyword, two or three attributes, and a condition. Titles that cram 12+ keywords usually end up keyword-stuffed and score worse with buyers even when Cassini indexes them.
Where do you put keywords in an eBay listing for best results?
In order of impact: the title, item specifics, and the first line of the description. The title does roughly 70% of the work for Cassini relevance. Item specifics cover filtered search. Description keywords help the listing show up in Google's external indexing of eBay pages but have minimal effect inside eBay search.
Does eBay SEO work the same as Google SEO?
No. eBay's Cassini algorithm weights recent sell-through, click-through rate, and item specifics far more heavily than Google does. Backlinks and site authority — the foundation of Google SEO — don't exist inside eBay. Focus on listing-level signals: keyword-accurate titles, filled item specifics, quality images, and strong sales history.
How often should I update keywords in my eBay listings?
Every 30 days for your top 20 revenue-generating listings, and whenever impressions drop more than 20% month-over-month on any listing. Shopper language evolves — especially in fashion, tech, and trending product categories — and titles that worked six months ago lose ground to newer modifiers.
Can I use the same keywords across multiple eBay listings?
Yes, for different products. Listing the same SKU multiple times under different keywords is against eBay policy and trips duplicate-listing detection. But listing two different products that share a keyword (e.g., two different Carhartt jackets both using the term "Carhartt") is fine and standard practice.
Are promoted listings a substitute for good keywords?
No. Promoted Listings Standard runs on a cost-per-sale model and amplifies listings that already rank organically. A poorly keyworded listing won't get much from promotion because Cassini still won't show it to the right buyers. Fix the organic listing first, then layer promotion on top for an additional 10-30% impression lift.
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