amazon subject matter keywords

What is Amazon Subject Matter?

The Subject Matter fields consists of 5 text fields that you enter in order to make your Amazon listing look spiffy. Fifty characters allowed for each field, so there is adequate space to describe your product.

How to Become an Expert

Amazon’s ranking algorithm is a mystery, but we’ve been told that placing keywords in the content text fields is the most important and effective way to increase your rankings. More than bullets and description backend search terms, keywords are what readers and potential buyers will see first.

This has been verified by data from several top sellers I know personally on smaller scale tests.  We’ve seen 7 and 8 figure Amazon FBA sellers replicate these results.

By adding keywords to listings not indexed, you’re able to index over and over.  The proof is in the pudding.

You can tell from the title, “Subject Matter,” that Amazon A9 uses these fields to determine the proper categorization or context for a product.  This means that you should be using your top long tail search terms for the most effective categorization of your products.

The reason this is accomplished in the Subject Matter and not the Title & Listings is simple.  Amazon wants the customer-facing content to be more readable, creating a better user experience.  If the algorithm weighted long tail keywords as highly in the title and bullets, sellers would be incentivized to keyword stuff their content.  Thus, Amazon keeps the Subject Matter as a key ranking criterion to combat keyword stuffing.

Optimizing Subject Matter Fields

Amazon provides five  Subject Matter keyword fields, each with a maximum of 50 characters.  We recommend taking your top 7 to 10 long tail keyword phrases and inputting them throughout the five fields.  Naturally, these phrases will already be included within your title and bullet points.  Based on what we’ve seen, we recommend using each of your keywords 3 times total.

So, if your top 2 search phrases are “nerf gun targets for kids & “kids toy guns,” then both should be in your title.  That said, you can combine phrases with overlap into one Subject Matter field.

Here’s an example of what the Subject Matter keywords could look like.  See how each Subject Matter field has the full long tail keyword phrase and not just an individual keyword.

subject matter amazon keywords

It’s important to note that Amazon doesn’t always allow your listing to index for every variation of the same root keyword.  We’ve noticed that sometimes you’ll be able to index for all and sometimes you’ll only index for a few of the root keyword variations in your listing.

Identifying Long Tail Keyword Phrases

Amazon keyword research is one of the core staples of listing optimization.  There are 2 main factors to include a long tail keyword as a main search phrase.

  1. Phrase needs to describe the product in its entirety
    • Broader long tail keywords will not do this.  Here’s an example.  If you’re selling  Rubber iPhone 13 phone cases but your keyword is “rubber phone case,” it’s too broad to be considered a main search phrase.  The phrase “rubber phone case” doesn’t narrow a target audience enough, as Android users would search this only to be disappointed when your product listing is mismatched from their needs.
    • The broader the search, the lower the Amazon conversion rate.  Specificity is the key to obtaining clicks from shoppers who are likely to buy.
  2. Long Tail keyword must have High Search Volume
    • Ensure the keywords you’re inputting into the Subject Matter fields have sufficient search volume.  We’ll refrain from providing a set search volume number to follow, but in general you want keywords with a search volume of 1000+.

Best way to identify Amazon keywords?

Use Helium 10’s Magnet and Cerebro.  Magnet allows you to input any search term and identify volume for all similar results.  Cerebro allows you to run Reverse ASIN searches on your own listing and  competitor listings to generate the keywords that are both relevant and have sufficient search volume.

Steps to Crafting Amazon Subject Matter

  1. Choose 7 to 10 Amazon long tail phrases via Helium 10’s Magnet & Cerebro
  2. Input the phrases into the five Subject Matter fields, and ensure these phrases are in the keywords and descriptions
  3. Lock the changes in by saving them in Amazon’s back end
  4. Track your keyword ranking via Helium 10’s Rank Tracking tool

This process can be tedious, but it’s relatively straight-forward once you’ve selected your phrases.

Need guidance on how to optimize an Amazon Product Listing?

Check out our FBA Global in-depth articles on

If you have any questions or comments, reach out to us at FBA Global.  We’d be happy to connect with you.

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