What Is the Amazon A9 Algorithm?
A9 is the common name for Amazon's product search ranking algorithm, which decides which products appear for a search and in what order, based mainly on relevance to the query and the product's sales performance.
The name comes from A9.com, the Amazon subsidiary that built its search technology. Amazon does not use the label in public anymore, and some sellers call the current version A10. Either way, the system ranks products to show the ones shoppers are most likely to buy.
What it looks at
Amazon describes the factors only in general terms. The ones sellers and agencies work with:
- relevance: whether the search words appear in the title, bullets, backend search terms and other attributes
- performance: sales history, conversion rate and click-through rate for that search
- availability and price: an in-stock, competitively priced offer, often tied to holding the Buy Box
- delivery speed and customer experience signals
Why it matters
Organic rank on high-volume searches is the cheapest traffic a brand gets. Brands use ads to support rank because ad-driven sales count toward a product's sales history.
Common mistake
Treating ranking as keyword stuffing. Indexing gets you into the results, and sales velocity and conversion decide where you sit. Our article on how Amazon ranking works goes through the factors and how to move up.