How the Amazon A10 algorithm works: Simple breakdown

The Amazon A10 algorithm: A step-by-step breakdown of the ranking process

Most sellers think Amazon ranks products the same way Google does. Check the keywords, count the clicks, push the winner up. Wrong. Multiple filters run before your listing even shows up in results. By the time the page loads, a lot's already been decided.

Here's each stage, in order.

Step 1: The customer enters a search query

Your listing isn't involved yet. Amazon's reading the search first.

Not just matching words either. Its AI-powered knowledge engine, COSMO, works out what the buyer actually needs, pulling meaning from the query rather than just scanning for keyword matches. It interprets buyer intent. It understands context.

• A search for "shoes for a wedding" surfaces formal dress shoes, not trainers with "wedding" in the title
• The system maps search queries to product types, attributes, and substitute brands automatically
• Context, not just keywords, determines which listings even enter the pool

Pro tip: Listing copy that describes actual use cases tends to outperform copy stuffed with disconnected keyword strings. Write for the buyer first; COSMO's doing the same thing.

Step 2: Eligibility filtering

Hard filter. No exceptions. Listings missing basic requirements get cut before any ranking happens at all. Understanding Amazon listing optimization fundamentals is what keeps you from failing this filter before the race even starts.

A listing must have all four to survive it:

• A main product image (white background, TOS-compliant)
• A valid, active price
• In-stock inventory
• Prime eligibility or Buy Box qualification

Miss any one of them, and the listing drops out of the results completely. Copy quality is irrelevant at that point. Inventory management and Buy Box health sit at the foundation; call them what they are, ranking prerequisites.

Step 3: Relevance scoring

Now Amazon checks whether your listing actually matches what was searched. Your title, bullet points, product description, and backend search terms all get read. Filler words and punctuation get stripped out; only the keyword signals matter.

• Backend keywords cap at 249 bytes; pack them with synonyms, alternate spellings, and regional variations
• The title carries the most relevance weight; primary keywords should appear early
• Bullet points and descriptions pick up secondary and long-tail terms, but the title can't hold

Getting indexed for a keyword is one thing. Actually ranking for it is another. Most sellers blur the two. The gap between them opens right here, at relevance scoring. Do your Amazon keyword research properly, and your listing moves through. Skip it, and you stall.

Step 4: Performance signowal scoring

Relevance gets you considered. Performance is what gets you ranked. Amazon scores each listing based on how it's actually performed, then uses that score to decide placement. The signals it pulls include:

• Organic sales velocity (the heaviest-weighted factor)
• Conversion rate, meaning page visits that result in a purchase
• Click-through rate from search results
• Customer reviews and star ratings
• Seller authority, including ODR, late shipment rate, and return rates
• External traffic that converts on Amazon

Someone searched, found your listing, and bought without touching a single ad. That's the sale Amazon weighs most heavily. Paid traffic pushes velocity numbers up, sure, but organic demand is what the algorithm actually rewards.

Pull up the ACOS calculator, map your ad spend against organic performance, and find out where sales are really coming from.

Step 5: Behavioral and personalization layer

Two people run the same search. Results look different for each of them. Amazon pulls individual purchase history, browsing patterns, and repeat search behavior into the equation, so what one shopper sees is built around their own activity.

• A buyer who regularly purchases running gear will see different results for "water bottle" than someone with no fitness purchase history
• Repeat purchases of your product signal quality and push your visibility up for that customer segment
• Purchase frequency and search history both feed into how the algorithm weights your listing per user

Buyers who've purchased from you before are more likely to see your listings surface again. Brand loyalty has an algorithmic benefit, not just a marketing one. Watch your Amazon sales ranking; it shows how well those repeat behavioral signals are stacking up.

Step 6: External signal evaluation

Shopper finds your product on Google, through a blog, or via an influencer. They click through and buy on Amazon. The algorithm reads that as market validation. It's a live signal, not a one-time boost, and it keeps feeding the ranking as long as converting traffic keeps arriving.

• Traffic that converts pushes organic rankings up across relevant keywords
• Traffic that doesn't convert works against you; bounce-heavy campaigns actively drag rankings down
• Amazon Attribution is how you find out which outside sources are actually driving purchases, not just clicks

The more credible the source, the higher the conversion rate, and the more ranking weight it carries. An experienced Amazon account management agency can set up external traffic campaigns built to convert, not just drive clicks.

Step 7: Continuous re-ranking

Rankings aren't set and held. The algorithm re-evaluates constantly, adjusting positions based on what's happened recently across every signal above.

• A stockout can erase months of ranking progress within days
• A sudden spike in returns or a drop in conversion rate triggers a downward re-rank
• Consistent performance compounds; organically earned rankings hold longer than those propped up by ad spend

Where you rank right now is just a read of recent performance. Nothing locked in. Nothing permanent. Sellers who hold positions for months do it by running this as an ongoing process, checking signals weekly, not once a quarter.

The TACOS calculator sits alongside ACoS for a reason; total ad spend against total revenue tells you whether organic momentum is doing real work or whether paid spend is still holding everything up.

Nail each stage, and the rankings build. Let one slip, and the whole sequence breaks down.

Amazon A9 vs A10: The exact differences every seller needs to know

A9 didn't disappear. A10 is built on top of it. Sellers who missed that distinction either abandoned fundamentals that still work or kept running A9 playbooks on a system that had already moved on. Both groups paid for it.

Here's every major factor, what it looked like under A9, and where it stands now.

A10 didn't scrap A9. It added signals and re-weighted the existing ones. Sellers who stopped keyword work or dropped CVR tracking after reading about A10 handed positions to competitors who kept doing both. Those fundamentals still run results.

What shifted is where Amazon looks for proof that a product deserves to rank. Under A9, that proof came entirely from inside the platform. Sales, keywords, conversions. Under A10, external demand signals and seller credibility sit alongside those internal metrics. Both sides now matter.

Rankings drifting with no obvious listing change or sales drop? Seller authority is the first place to look. ODR, late shipment rate, and NCX scores in the Voice of the Customer dashboard drag positions down quietly, often weeks before a seller notices anything off.

Sales velocity and conversion shaping visibility

Amazon doesn’t reward effort; it rewards outcomes. Rankings move when sales velocity builds, and conversion holds, not when listings just look optimized. Every stage you’ve seen feeds into that loop. Traffic, keywords, reviews, all of it only matters if it turns into consistent buying signals.

If you’re seeing traffic but not movement, something in that chain is breaking. That’s where we come in. At Olifant Digital, we work directly on the signals that move rankings, from conversion to sales momentum, so your listings don’t just get seen, they stay there.