June 23, 2020

How to Harness the Power of Amazon’s A9 Product Search Algorithm

One of the first things anyone who visits Amazon does is to click on the search bar and type in what they are looking for. Savvy users may narrow down their search by clicking on sub categories, but most of us rely on Amazon’s top of search results, Best Seller and Choice badges to help us with our shopping. So, what does it take to rank products on Amazon?

In this article we will discuss:

  • What is Amazon’s A9 Algorithm?
  • How Product Search Works on Amazon
  • Amazon Ranking Metrics
  • Conversion Factors
  • Search Engine Optimization (SEO) Factors

I’ve helped improve the ranking of hundreds of products on Amazon by having an intimate understanding of how users search on Amazon and how to properly set up a listing for search. I’m going to share with you some tips that you can immediately apply to your listings to improve your product rankings in search results.

Let’s do this! :)

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What is the A9 Algorithm?

Amazon’s A9 is actually a subsidiary of Amazon, and is responsible for search results, advertising technology, and ranking of products associated with specific keywords from an organic and sponsored products perspective. The A9.com group is located in Downtown North, Palo Alto.

A brief history of A9.com

The name A9 was chosen as a numeronym to represent ‘A’ + 9 other letters. Under the lead of its first president, Udi Manber, A9 focused on product search and search advertising platforms. The algorithm is responsible for search on Amazon as well as other Amazon-owned websites like Audible.com, IMDB, Zappos, Good Reads and Twitch, to name but a few. One of the factors influencing Amazon to create their own search algorithm was that Google was better at indexing their own product detail pages than they were.

Some notable advancements from A9.com include “search inside the book” capabilities, which allowed customers to search through the full text of books.

Visual search, which uses augmented reality to provide both object and barcode recognition.

Lastly, Advertising technology, which delivers sponsored product links across the web and on all Amazon properties. This allows for advertising programs like Amazon DSP or the Sponsored Display Beta inside the Amazon Advertising Console.

The major difference between Amazon’s search engine versus Google or Facebook is that Amazon’s search is based on product-oriented searches, with the goal of getting a sale. Because all searches are product-based and less informational, this allows the algorithm to disregard queries that have “how to”, or “best” in the search and focus on the root keywords that are the most relevant and likely to lead to a sale.

This is very different from Google, whose data is based on browser data and provides targeting throughout the search journey. Also, A9 is very different from Facebook or social media in general, which is based on users’ demographic information and preferences based on social engagement, i.e. likes, follows, comments, etc.

Amazon’s data is the best when it comes to understanding how customers search when they are closest to the point of purchase. The A9.com group over the years has perfected its ability to perpetuate Amazon’s Mission, which is; to be Earth’s most customer-centric company, where customers find and discover anything they might want to buy online.

How Product Search Works on Amazon

Product search is directly influenced by Sales Performance, Text Match Relevancy, Price and Availability. From a sales perspective, the metrics you should be considering are the Click-through Rate (CTR) of your listings, Conversion rate on a product page, and overall sales. The indirect factors that influence search include fulfillment method, review quality and count, images, enhanced brand content or A+ content, advertising and promotions. All of the indirect factors lead to a better user experience on the platform, which will lead to more sales. Let’s dive deeper into the factors that influence Amazon’s search engine ranking.

Amazon Ranking Metrics

Now that we have an understanding of Amazon’s A9 algorithm and how products are ranking on Amazon, let’s break down some of the metrics you should be aware of when trying to figure out which levers need to be pulled to improve ranking.

Conversion Factors

Best Seller Rank (BSR)

Amazon’s BSR is calculated based on Amazon sales and is updated hourly to reflect recent and historical sales of every item sold on Amazon. The BSR is a good indicator of how well a product is selling overall in a particular category and sub category. You can compare this data with some of the top sellers in your niche to get an idea of how your competitors are ranking compared to your products.

Customer Reviews

Customer reviews are the equivalent of currency on Amazon; the more reviews you have, the more social validation you have. This is making your listing more likely to get a click (improved CTR) and more likely to be trusted as a quality product (provided those reviews are all good). When considering advertising, we recommend that your product is retail ready, i.e. at least 15 reviews with more than a 4-star rating.

A+ Content (Formerly Enhanced Brand Content)

A+ content is available to sellers who are Brand Registered and gives us the ability to incorporate additional content in our product detail pages in order to influence a purchase. This is a great way to stand out from your competitors.


Having your products on Amazon doesn’t necessarily mean it’s a race to the bottom. But, it is important that you are competitively ranked if you want to maximize your sales velocity on the platform. If your products are at a higher price point than average, it’s important that you have the validation (reviews) and enhanced brand content (A+ content) in order to showcase your unique selling proposition. Keep in mind that there are different strategies for promoting higher-priced items on Amazon.


Advertising on Amazon is a great way to get your products in front of potential customers who are searching for them. Unlike Google Ads, advertising on Amazon will influence organic ranking because it perpetuates sales. We recommend both an on- and off-amazon advertising strategy when promoting products.

Answered Questions

Answering questions helps other customers understand aspects of your products that may have been missed on your listing. It also gives you an idea of different features or pain points you should address in your listing to ensure the best user experience.

Search Engine Optimization (SEO) Factors


A product title should incorporate high volume and relevant search terms in a reader-friendly format. Generally, you should aim to have 2-3 high-value keywords using between 125 and 200 characters. Keep in mind that the first 70 characters will be visible on mobile devices. Consider using a formula to ensure consistency across your catalog. An example formula may look like this:

*Note: Some categories are limited to 50 characters. Be sure to check category-specific guidelines before starting optimization.


Product bullets help sell your product. Yes, they are indexed. However, consider that a user has already clicked over to your product page. The title (amongst other factors) was relevant enough to drive traffic. At this point, you should consider the top five features of your product that can help influence a sale.


The description is for the most critical buyers. It’s also indexed for search, but has much less weight than the title or bullets. Use HTML to format the description in a user-friendly format. Avoid duplicating your bullets and include other features that you were not able to incorporate in your listing. Consider what comes in the package, dimension of products, a bit about the manufacturer, or anything else that a customer might ask themselves when considering a purchase.

Backend Search Terms

Backend search terms are not visible to those viewing your product detail page, but are located on the backend, where you edit your listings structured data. This is where you incorporate keywords that are not featured in your title, bullets and description. Consider going after complementary products, synonyms, hypernyms and spelling variations. Here is what Amazon has to offer on using Search Terms Effectively (must be logged into Seller Central).


To wrap things up, I’d like to share with you one of my favorite Amazon SEO jokes: Where is the best place to bury a body?… Give up? On the second page of search results.

I’m making light of the importance of ranking your product on Amazon. The reality is, it’s the biggest difference between getting sales on Amazon and not. As of April 2019, there are 119,928,851 products on Amazon, and growing. In the US alone, Amazon sells 4,000 products every minute. Amazon represents 50% of all eCommerce sales in the US.

These numbers should tell you that Amazon isn’t going anywhere. If you are going to succeed in this digital age, you need to have a user experience on the Amazon platform; you need to control that experience, and you need to ensure that you are keeping customers happy at every  touchpoint (on and off Amazon).

Only by understanding the fundamentals of how the A9 algorithm works, and what you can do to improve your product rankings and sales, will you push your brand to the next level.

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Read further:

91% of bestseller listings contain A+ content, while, for non-bestseller listing, the number is just 70%. With access to high-quality data, we've discovered which are the best success tactics when it comes to listing optimization: The Anatomy of a Bestselling Amazon Listing