What is Amazon's A9 algorithm

What is Amazon’s A9 algorithm and how does it work?

In a marketplace as highly saturated and deeply competitive as Amazon, it may seem difficult, if not impossible, to improve the ranking and visibility of your products. However, if you are familiar with the A9 algorithm and know how to implement an effective SEO strategy on Amazon, you can increase the visibility of your products and position them among the top search results in their category.

If you don’t have a thorough understanding of Amazon’s A9 search engine and understand its nuances, you will not only be losing traffic and sales, you will also be missing out on the competition, missing out on the opportunity to raise awareness of your product and your brand.

In this practical guide we provide you with information that will help you understand how Amazon’s A9 algorithm works and what are the best practices to achieve higher rankings.

What is Amazon SEO?

SEO stands for Search Engine Optimisation. It is the process of increasing the quality and quantity of traffic that is generated from organic search results displayed by search engines. Although Google’s search engine is currently the best known, Amazon’s search engine (A9) works quite differently.

How does Amazon’s A9 search algorithm work?

Amazon’s algorithm is known as A9. If you search on Amazon, you are using the A9 search engine. To perform a search at scale, Amazon’s search engine and algorithms determine which items best match the customer’s query and rank them according to how relevant they are to the consumer.

Amazon’s ranking algorithms automatically learn to combine multiple relevance features. They analyse past search patterns to adapt to what is most important to customers. As mentioned above, Amazon searches are transactional and not informational.

 When you upload a product to Amazon (indexing), the algorithm reads, above all, the title, the search terms and the category node for which you have indexed it. From there, rank your product for different search terms. Note that this will not make your product rank better, but will make it rank better in its category.

The A9 search algorithm is based on two basic principles: performance and relevance. Amazon charges you a commission for every sale you make and therefore its A9 algorithm is designed to make it earn higher profits. The more sales your product generates (and the more money Amazon makes), the better it will rank for the search terms for which you have already achieved conversions.

The three main functions of Amazon A9 are: indexing, ranking and delivering the most relevant results (the ones that generate the most sales and commissions) to the customer’s search term. Therefore, although it is essential to generate good keyword research so that your product ranks for the right keywords, the most important thing to position it well will be sales.

Another thing you should never forget is the stock. Remember that Amazon’s objective is to sell and, therefore, it will not position your products with low stock or stock-outs. Breaking the stock will be like going back to square one in terms of positioning. Be very careful with this DOOS (Days Out Of Stock) metric. This negative metric can be one of the reasons why your product does not appear in searches.


Consider how much money Amazon is making from your product. The more sales you generate, the more profit Amazon will make and the more priority it will give to products that have a higher conversion rate.


Reviews and ratings are highly relevant when it comes to improving the organic positioning of your products. They will give you authority over your competitors’ articles. The more reviews and better ratings your product gets, the more your conversion rate will increase. You could say that Amazon reviews are the equivalent of Googlelinks. The more you get and the better quality they are, the more authority and relevance the algorithm will give you.

Remember: Amazon rewards listings that work not keyword stuffed listings.


Being on the first page of Amazon will ensure your visibility. If your product listing is relevant, you will generate sales, and if your product is of high quality, you will receive good reviews. The vast majority of clicks to products, in a market as large as Amazon’s, take place on the first page of search results, underlining the critical importance of being on the first page.
The question then becomes: How do I get on the first page of results if my product is new, I have no reviews, and I have not generated any sales?

You will have to design a good launch strategy to generate your first sales through Amazon Advertising campaigns, offers, coupons and promotions. It is important that you are clear about the objectives of your Amazon Advertising campaigns. If you are overly concerned with KPIs like ACOS in the launch phase, you will only be measuring how profitable your CAMPAIGN is NOW, but you will not be measuring how profitable your ACCOUNT will be AFTER.


Carlos Sánchez

Head of Marketing Strategy | Nozama Solutions