Amazon Dynamic Pricing and the A10 Algorithm: How Your Price Affects Rankings

Amazon is not a search engine. It is a store. The practical difference is significant: Google ranks results by relevance, and purchase intent is inferred. Amazon ranks results by purchase likelihood, and relevance is a filter applied first.

The implication for pricing: your product's price is not only a Buy Box variable. It is a ranking signal. A competitive price drives conversion rate. Conversion rate drives sales velocity. Sales velocity drives organic search ranking. And organic search ranking determines which buyers see your listing without you paying for the placement.

TL;DR: Amazon's ranking algorithm (commonly called A9 or A10 , Amazon's own name for the current version is not publicly confirmed) prioritises products most likely to generate a sale. The chain is: price affects conversion rate, conversion rate affects sales velocity, sales velocity is the primary performance signal the algorithm weighs. Repricing that maintains competitive pricing at a sustainable margin sustains the conversion rate that feeds organic ranking. This guide explains each link in the chain and how to configure repricing to use it.

What is Amazon's A9 / A10 algorithm?

Amazon's search ranking algorithm determines which products appear in which position when a buyer searches on Amazon.com. The algorithm is commonly referred to as A9 (after Amazon's search subsidiary, A9.com) or A10 in seller communities , though Amazon does not use these labels in its official documentation.

What Amazon does confirm, through its seller guidance and published statements, is that its algorithm optimises for purchase likelihood. The question the algorithm answers is not "which listings are most relevant to this query" but "which listings are most likely to result in a purchase for this buyer at this moment."

This distinction shapes how every ranking factor works:

A product listing must first be eligible for a search result , its content must contain the relevant keywords, and its seller must meet basic quality standards. Eligibility is the relevance filter.

Among eligible listings, the algorithm then ranks by performance signals , primarily conversion rate, sales velocity, and click-through rate. The listing that converts best for this search query ranks highest.

The algorithm continuously updates based on real-time and rolling performance data. A listing that sold well last month but has stalled this month slides in ranking. A listing with a sudden velocity spike rises. The ranking reflects current performance, not historical authority.

This is the fundamental reason why pricing is a ranking variable, not merely a competitive variable. A price change that affects conversion rate affects ranking.

The ranking factors Amazon weights most heavily

Amazon's algorithm weighs six categories of signal when determining organic search rank. Conversion-related factors dominate the performance tier.

1. Conversion Rate (CVR): The percentage of buyers who click on your listing and then complete a purchase. This is the algorithm's primary performance signal. A listing with a 15% CVR on a given keyword outranks a listing with 5% CVR, all else being equal. CVR is directly affected by price , a listing priced competitively relative to alternatives converts at a higher rate than one priced significantly above alternatives.

2. Sales velocity: Units sold per day, per week, and over trailing periods. The algorithm rewards listings with sustained and growing velocity. A sudden velocity increase , from a promotion, a price change, or an advertising surge , triggers an upward ranking adjustment. Velocity that falls signals underperformance, and ranking declines.

3. Click-through rate (CTR): The percentage of buyers who click on your listing when it appears in search results. CTR is affected by the listing's title, primary image, price, and star rating as displayed in the search results card. A lower price (relative to competing listings on the same search results page) contributes to higher CTR.

4. Keyword relevance: How well the listing's title, bullet points, backend keywords, and description match the search query. Relevance is an eligibility factor more than a ranking factor , it determines whether you appear for a search, not necessarily where.

5. Seller performance metrics: Account health signals including Order Defect Rate, Late Shipment Rate, and feedback score. Poor metrics do not directly lower search rank, but they affect Buy Box eligibility, which in turn affects conversion rate and velocity.

6. Inventory availability: Out-of-stock listings lose ranking rapidly. The algorithm deprioritises listings that cannot fulfil orders. A seller who runs out of stock on a high-ranking ASIN often returns to a significantly lower position after restocking, requiring a velocity rebuild to recover.

How sales velocity affects organic ranking

Sales velocity is Amazon's equivalent of a ranking score. The more units an ASIN sells in a given period, the stronger its ranking signal , and the higher its position in search results for relevant queries.

Amazon tracks Best Seller Rank (BSR) as a public proxy for velocity. BSR is updated hourly and reflects recent sales relative to other products in the same category. A product with BSR 500 in its category is selling significantly more than a product with BSR 5,000.

BSR is correlated with, but not identical to, organic search ranking. Organic ranking is query-specific , a product ranks differently for "kitchen knife" than for "chef knife" , while BSR is category-wide. Both respond to the same underlying signal: units sold per period.

According to Jungle Scout's seller research, 56% of Amazon customers start their product searches on Amazon rather than Google. For those customers, organic search ranking determines which products they see first. A sustained velocity above competitors produces and holds the top positions in search results for the target queries.

The velocity trap works in both directions:

Rising velocity: More sales → better ranking → more organic traffic → more sales. A positive feedback loop that, once established, is self-sustaining at the right price.

Declining velocity: Fewer sales → weaker ranking → less organic traffic → fewer opportunities to sell. A negative feedback loop that compounds over weeks if not interrupted.

Pricing is the fastest lever available to shift velocity in either direction. A well-timed price reduction on a stalling ASIN generates a velocity spike that the algorithm registers and rewards with improved ranking.

The price → conversion → velocity → rank chain

The mechanism connecting price to organic ranking runs through four sequential links. Each link is measurable. Pricing decisions affect every link in sequence.

Link 1: Price affects conversion rate.

On a listing where multiple sellers compete for the Buy Box, the competitive price directly influences how many buyers complete a purchase vs. how many click away to compare alternatives. A listing at $24.99 in a market where alternatives range from $22 to $28 converts well. The same listing at $29.99 converts less well , some buyers see the alternatives as better value.

WebFX (citing Wiser data) confirms that 90% of Amazon shoppers compare prices when shopping on the platform. Price is the visible signal buyers act on most quickly. Conversion rate reflects those decisions directly.

Link 2: Conversion rate drives sales velocity.

For a given level of traffic, a higher conversion rate produces more sales. More sales per period = higher velocity. The algorithm observes both the conversion rate (how well the listing performs per impression) and the velocity (how many units move per period). Both feed ranking.

Link 3: Sales velocity determines organic ranking.

The algorithm ranks listings that sell more over competing listings that sell less. A velocity increase, sustained for 7 to 14 days, produces a measurable improvement in search ranking for the target keywords. A velocity decline, sustained for the same period, produces a measurable decline.

Link 4: Organic ranking determines organic traffic.

A listing in position 1 to 3 on a relevant search result page receives dramatically more clicks than a listing on page 2 or below. According to Marketplace Pulse, over two-thirds of clicks go to the first page of Amazon search results. Organic ranking is not a vanity metric , it is the primary determinant of unpaid traffic.

The chain completes the loop: better organic ranking → more organic traffic → more opportunities to convert → higher velocity → better organic ranking.

How repricing improves your Amazon SEO beyond the Buy Box

Repricing affects organic ranking through its effect on conversion rate and velocity, not directly through any search algorithm signal. The mechanism is indirect but real and measurable.

A repricer that holds your price competitive against the Buy Box maintains the conversion rate that feeds velocity. When a competitor drops their price and your rule does not respond, buyers see a price gap , and some portion of them choose the cheaper option. Each lost conversion is a lost velocity signal.

A repricer that responds correctly holds your price near the competitive range, maintaining conversion rate and the velocity that follows from it.

The ranking benefit of correct floor pricing:

A floor set below your real break-even produces sales at a loss. It also produces velocity, which produces ranking. For some sellers, this is an intentional strategy during a launch phase , run below break-even temporarily to generate the velocity needed to rank, then raise prices once ranking is established. This is a recognised launch strategy and it works precisely because velocity is the primary ranking signal.

A floor set too high , above the competitive range , suppresses conversion rate and velocity. The ranking declines. The platform shows the listing to fewer buyers. Which makes recovery progressively harder.

The most efficient repricing for ranking:

A match-rule repricer (not undercut) holds price at the competitive level without triggering spiral dynamics. Stable competitive pricing produces stable conversion rate and stable velocity. Stable velocity produces stable ranking.

Oscillation repricing, as described in the oscillation repricing guide, adds a hold-price phase that increments above the competitive range during off-peak hours. If the conversion rate holds at the higher price, the velocity signal is only slightly affected. If the conversion rate drops significantly at the higher price, the velocity signal weakens. The repricing rule should be tested for ranking impact, not assumed to be neutral.

Book a Demo , use velocity-based repricing to maintain the conversion rate and sales volume that feed your Amazon organic ranking.

The click-through rate factor: how competitive pricing improves CTR

On an Amazon search results page, the buyer sees six to eight products before scrolling. Each product card shows a title, image, star rating, review count, and price. Price is the only number visible at a glance that directly signals value relative to alternatives.

A buyer searching for "kitchen knife set" sees a results page with eight listings. Seven are priced $28 to $35. One is $19.99. The $19.99 listing attracts disproportionate attention , its price signals value in a context where the buyer is actively comparing.

Whether the buyer clicks depends on the full card, including image quality and review count. But a significantly lower price increases the probability of a click, and click-through rate feeds the algorithm's ranking signal.

The relationship is not linear and it cuts both ways:

A price significantly below the market range improves CTR but signals potential quality concerns to some buyers. A low price on a product with strong reviews overcomes this signal. A low price with few reviews does not.

A price at or slightly below the category average on a search results page performs well on CTR without signalling distress pricing. This is the pricing range that repricing rules should target for CTR optimisation rather than marginal gains from extreme undercutting.

Sponsored Products advertising also contributes to CTR signals. Repricer's Buy Box guide covers how winning the Buy Box places Sponsored Products in the highest-converting ad positions, which contributes to the CTR signal that feeds ranking.

Keyword relevance vs performance signals: what matters more

Keyword relevance determines whether you appear for a search query. Performance signals determine where you appear. For most established listings, performance is more important than incremental relevance optimisation.

A listing with a keyword-optimised title, seven backend keyword fields completed, and a perfectly structured A+ Content page will appear in more search results than one with a sparse listing. That is the relevance benefit.

But among the listings that all appear for the same query, the one that converts best ranks first , regardless of whether its listing is more or less keyword-optimised than the others. The algorithm has enough performance data to rank by outcomes rather than by inputs.

The practical implication: for new listings with no sales history, keyword optimisation is the first priority because it determines eligibility. For established listings with an existing velocity and conversion history, pricing and velocity optimisation produces larger ranking gains than further listing optimisation.

This is why repricing is an Amazon SEO lever, not merely a competitive pricing tool. The listing is the eligibility signal. The price is the performance lever.

Where keyword relevance still matters:

New keywords. A listing that has ranked well for "kitchen knife set" and wants to rank for "chef knife set" needs the latter phrase in the listing content before performance data accumulates for that query. Relevance opens the door. Performance determines where you stand once inside.

Backend search terms, the A+ Content keyword field, and the product description all contribute to keyword indexing. These are one-time optimisations that improve eligibility breadth. Performance optimisation , including pricing , is the ongoing lever.

How to use velocity-based repricing to improve your organic rank

Velocity-based repricing uses sales rate as a trigger rather than competitor prices. When sales velocity drops below a target, the rule lowers price to recover velocity. When velocity is strong, the rule holds or raises price.

This is different from standard competitive repricing, which watches competitor prices. Velocity-based rules watch your own sales performance.

Configuring a velocity-based rule:

Set a target sales rate for the ASIN , for example, 8 units per day based on your historical average and your inventory position. Configure the rule to:

• If units sold in the trailing 24 hours are below 5 (below the target threshold by more than 30%), lower price by $0.50, minimum floor.

• If units sold in the trailing 24 hours are above 12 (above target by more than 50%), raise price by $0.50, maximum ceiling.

• If units sold are within the target range (5 to 12), hold the current price.

The ranking benefit:

When velocity drops , perhaps because a competitor restocked and is holding a lower Buy Box price , the velocity rule detects the sales decline and lowers your price to recover. The recovery keeps velocity in the range the algorithm associates with your current ranking. Without the velocity rule, the sales decline compounds into a ranking decline.

When velocity is strong , perhaps because a competitor is out of stock , the velocity rule captures the ceiling by raising price incrementally. This recovers margin without sacrificing the velocity signal, because at strong velocity the price increase does not yet significantly affect conversion.

The floor constraint:

Velocity rules require a floor calculated from actual costs. A velocity rule that recovers sales by lowering price below break-even generates velocity and ranking improvement at the cost of margin. Setting the floor correctly ensures the rule recovers velocity within the profitable price range rather than below it.

For the full floor calculation methodology, the Amazon seller fees guide covers every cost component in the minimum price calculation.

Key Takeaways

• Amazon ranks by purchase likelihood, not by keyword match. Relevance is the eligibility filter. Performance signals determine where you rank among eligible listings.

• The chain is: price → conversion rate → velocity → organic ranking. Each link is measurable. Pricing decisions affect ranking through this chain, not directly.

• 90% of Amazon shoppers compare prices. Price is the visible signal that affects CTR on search results pages. CTR feeds the algorithm's performance signals.

• Velocity-based repricing is the most direct way to use pricing as a ranking lever. It detects sales decline and responds before the decline compounds into a ranking decline.

• Keyword relevance matters more for new listings. Performance signals matter more for established ones. Once a listing is indexed for the target queries, velocity and conversion rate determine where it ranks.

Action Plan

1. Pull your current organic ranking for your top 3 target keywords. Use Seller Central's Search Query Performance report or a third-party rank tracker. This is your baseline before any repricing changes.

2. Pull your trailing 30-day conversion rate for those ASINs. This is visible in Seller Central under Business Reports, then Detail Page Sales and Traffic. Note the CVR per ASIN.

3. Check whether your current average selling price is within 5% of the Buy Box price. If it is consistently above Buy Box, your conversion rate is suppressed by price. A floor review is needed before a velocity-based rule makes sense.

4. Set a target daily velocity for each ASIN based on the trailing 30-day average. Configure a velocity-based trigger: if daily sales drop more than 30% below target, lower price by $0.50. If sales rise more than 50% above target, raise price by $0.50.

5. Monitor ranking weekly for 30 days after enabling the velocity rule. Check organic position for your 3 target keywords each Monday. A sustained velocity above baseline should produce measurable ranking improvement by week 3 to 4.

Frequently Asked Questions

What is the Amazon A9 or A10 algorithm?

Amazon's search ranking algorithm determines which products appear in which positions when a buyer searches on Amazon.com. In seller communities, it is commonly called A9 (after Amazon's search subsidiary, A9.com) or A10 (an informal reference to an updated version). Amazon does not officially use these version labels in public documentation. What Amazon does confirm is that its algorithm optimises for purchase likelihood , it ranks the listings most likely to result in a sale. Relevance to the search query determines eligibility. Performance signals , primarily conversion rate and sales velocity , determine ranking among eligible listings.

How does my price affect my Amazon ranking?

Price affects ranking through the conversion rate and velocity chain. A competitive price improves conversion rate , more buyers who see your listing complete a purchase. A higher conversion rate produces more sales per period, which is higher velocity. Velocity is the primary performance signal the algorithm weighs for organic ranking. A sustained velocity increase produces improved organic ranking. A sustained velocity decline produces ranking decline. Pricing is the fastest lever to move velocity in either direction.

What ranking factors does Amazon use?

The primary performance signals are conversion rate (what percentage of buyers who view the listing make a purchase), sales velocity (units sold per period), and click-through rate (how often buyers click the listing in search results). Supporting factors include keyword relevance in the listing content (determines eligibility for a query), seller performance metrics (affects Buy Box eligibility which feeds conversion rate), and inventory availability (out-of-stock listings lose ranking rapidly). Among these, conversion rate and velocity carry the most weight for established listings.

Does repricing improve my Amazon organic search position?

Yes, indirectly. Repricing does not directly send a signal to the search algorithm. It affects conversion rate by keeping your price competitive, which affects velocity, which the algorithm observably ranks. A repricer that holds your price at a competitive level relative to the Buy Box maintains the conversion rate and velocity that sustains your ranking. A velocity-based repricing rule detects sales decline and responds before it compounds into a ranking decline. The improvement is measurable over a 3 to 4-week window after configuring the velocity rule.

Does lowering my price always improve my ranking?

Not always. Lowering price below the competitive range improves conversion rate and velocity up to the point where buyers become suspicious of quality, or where the price falls below Amazon's reference price and triggers Fair Pricing Policy suppression. Pricing below your floor produces velocity at a loss: the ranking improves while the margin erodes. The optimal pricing for ranking is at or slightly below the competitive Buy Box price on your listing, with a floor that reflects actual costs. Velocity-based rules adjust within this range based on observed sales performance rather than competitor price moves.

Book a Demo , use velocity-based repricing to maintain the sales rate that feeds your Amazon organic ranking and connect pricing performance to your ranking outcomes.